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Chemistry Faculty Publications

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Articles 91 - 120 of 165

Full-Text Articles in Biochemistry

Identification Of The Adp-L-Glycero-D-Manno-Heptose-6-Epimerase (Rfad) And Heptosyltransferase Ii (Rfaf) Biosynthesis Genes From Nontypeable Haemophilus Influenzae 2019, W A. Nichols, B W. Gibson, William Melaugh, N G. Lee, M Sunshine, M A. Apicella Jan 1997

Identification Of The Adp-L-Glycero-D-Manno-Heptose-6-Epimerase (Rfad) And Heptosyltransferase Ii (Rfaf) Biosynthesis Genes From Nontypeable Haemophilus Influenzae 2019, W A. Nichols, B W. Gibson, William Melaugh, N G. Lee, M Sunshine, M A. Apicella

Chemistry Faculty Publications

Haemophilus influenzae is an important human pathogen. The lipooligosaccharide (LOS) of H. influenzae has been implicated as a virulence determinant. To better understand the assembly of LOS in nontypeable H. influenzae (NtHi), we have cloned and characterized the rfaD and rfaF genes of NtHi 2019, which encode the ADP-L-glycero-D-manno-heptose-6-epimerase and heptosyltransferase II enzymes, respectively. This cloning was accomplished by the complementation of Salmonella typhimurium lipopolysaccharide (LPS) biosynthesis gene mutants. These deep rough mutants are novobiocin susceptible until complemented with the appropriate gene. In this manner, we are able to use novobiocin resistance to select for specific NtHi LOS inner core …

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Characterization Of A Transposon Tn916-Generated Mutant Of Haemophilus Ducreyi 35000 Defective In Lipooligosaccharide Biosynthesis, B W. Gibson, A A. Campagnari, William Melaugh, M A. Apicella, S Grass, Jing Wang, Katherine L. Palmer, R S. Munson Jan 1997

Characterization Of A Transposon Tn916-Generated Mutant Of Haemophilus Ducreyi 35000 Defective In Lipooligosaccharide Biosynthesis, B W. Gibson, A A. Campagnari, William Melaugh, M A. Apicella, S Grass, Jing Wang, Katherine L. Palmer, R S. Munson

Chemistry Faculty Publications

To define the role of the surface lipooligosaccharide (LOS) of Haemophilus ducreyi in the pathogenesis of chancroid, Tn916 mutants of H. ducreyi 35000 defective in expression of the murine monoclonal antibody (MAb) 3F11 epitope on H. ducreyi LOS were identified by immunologic screening. One mutant, designated 1381, has an LOS which lacks the MAb 3F11 epitope and migrates with an increased mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The gene disrupted by the Tn916 element in strain 1381 was identified by cloning the sequences flanking the Tn916 element. The sequences were then used to probe a lambda DASHII genomic library. …

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Nerve Tissue-Specific Human Glutamate Dehydrogenase That Is Thermolabile And Highly Regulated By Adp / P. Shashidharan, Donald D. Clarke, Naveed Ahmed, Nicholas Moschonas, And Andreas Plaitakis Department Of Neurology, Mount Sinai School Of Medicine, New York; Department Of Chemistry, Fordham University, Bronx New York, Usa; And Department Of Biology And School Of Health Sciences, University Of Crete, Crete, Greece, P. Shashidharan, Donald Dudley Clarke Phd, Naveed Ahmed, Nicholas Moschonas Jan 1997

Nerve Tissue-Specific Human Glutamate Dehydrogenase That Is Thermolabile And Highly Regulated By Adp / P. Shashidharan, Donald D. Clarke, Naveed Ahmed, Nicholas Moschonas, And Andreas Plaitakis Department Of Neurology, Mount Sinai School Of Medicine, New York; Department Of Chemistry, Fordham University, Bronx New York, Usa; And Department Of Biology And School Of Health Sciences, University Of Crete, Crete, Greece, P. Shashidharan, Donald Dudley Clarke Phd, Naveed Ahmed, Nicholas Moschonas

Chemistry Faculty Publications

Glutamate dehydrogenase (GDH), an enzyme that is central to the metabolism of glutamate, is present at high levels in the mammalian brain. Studies on human leukocytes and rat brain suggested the presence of two GDH activities differing in thermal stability and allosteric regulation, but molecular biological investigations led to the cloning of two human GDH-specific genes encoding highly homologous polypeptides. The first gene, designated GLUD1, is expressed in all tissues (housekeeping GDH), whereas the second gene, designated GLUD2, is expressed specifically in neural and testicular tissues. In this study, we obtained both GDH isoenzymes in pure form by expressing a …

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Protein-Protein And Protein-Dna Interactions At The Bacteriophage T4 Dna Replication Fork. Characterization Of A Fluorescently Labeled Dna Polymerase Sliding Clamp, Daniel J. Sexton, Theodore E. Carver, Anthony J. Berdis, Stephen J. Benkovic Nov 1996

Protein-Protein And Protein-Dna Interactions At The Bacteriophage T4 Dna Replication Fork. Characterization Of A Fluorescently Labeled Dna Polymerase Sliding Clamp, Daniel J. Sexton, Theodore E. Carver, Anthony J. Berdis, Stephen J. Benkovic

Chemistry Faculty Publications

The T4 DNA polymerase holoenzyme is composed of the polymerase enzyme complexed to the sliding clamp (the 45 protein), which is loaded onto DNA by an ATP-dependent clamp loader (the 44/62 complex). This paper describes a new method to directly investigate the mechanism of holoenzyme assembly using a fluorescently labeled cysteine mutant of the 45 protein. This protein possessed unaltered function yet produced substantial changes in probe fluorescence intensity upon interacting with other components of the holoenzyme. These fluorescence changes provide insight into the role of ATP hydrolysis in holoenzyme assembly. Using either ATP or the non-hydrolyzable ATP analog, adenosine …

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The Carboxyl Terminus Of The Bacteriophage T4 Dna Polymerase Is Required For Holoenzyme Complex Formation, Anthony J. Berdis, Patrice Soumillion, Stephen J. Benkovic Nov 1996

The Carboxyl Terminus Of The Bacteriophage T4 Dna Polymerase Is Required For Holoenzyme Complex Formation, Anthony J. Berdis, Patrice Soumillion, Stephen J. Benkovic

Chemistry Faculty Publications

To further elucidate the mechanism and dynamics of bacteriophage T4 holoenzyme formation, a mutant polymerase in which the last six carboxyl-terminal amino acids are deleted, was constructed, overexpressed, and purified to homogeneity. The mutant polymerase, designated ΔC6 exo−, is identical to wild-type exo− polymerase with respect to kcat, kpol, and dissociation constants for nucleotide and DNA substrate. However, unlike wild-type exo− polymerase, the ΔC6 exo− polymerase is unable to interact with the 45 protein to form the stable holoenzyme. A synthetic polypeptide corresponding to the carboxyl terminus of the wild-type exo− polymerase was tested as an in vitro inhibitor of …

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The Lipooligosaccharides Of Haemophilus Ducreyi Are Highly Sialylated, William Melaugh, A A. Campagnari, B W. Gibson Jan 1996

The Lipooligosaccharides Of Haemophilus Ducreyi Are Highly Sialylated, William Melaugh, A A. Campagnari, B W. Gibson

Chemistry Faculty Publications

The major lipooligosaccharides of the sexually transmitted pathogen Haemophilus ducreyi 35000 have been previously found to terminate in N-acetyllactosamine and sialyl-N-acetyllactosamine, Neu5Ac alpha 2-->3Gal beta 1-->4GlcNAc (W. Melaugh, N. J. Phillips, A. A. Campagnari, M. V. Tullius, and B. W. Gibson, Biochemistry 33: 13070-13078, 1994). In this study, mass spectrometry and composition analyses have shown that the lipooligosaccharides from three other H. ducreyi strains also contain N-acetyllactosamine and are highly sialylated (approximately 30 to 50%), although one African strain was found to contain neither of these structural features.

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Preparation And Fungitoxicity Of 3-Bromo-6-Chloro- And 6-Bromo-3-Chloro-8-Quinolinols / Gershon H., Clarke D. D., Gerhson M, Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa, New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 1996

Preparation And Fungitoxicity Of 3-Bromo-6-Chloro- And 6-Bromo-3-Chloro-8-Quinolinols / Gershon H., Clarke D. D., Gerhson M, Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa, New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

3-Bromo-6-chloro- and 6-bromo-3-chloro-8-nitro, -8-amino-, and -8-hydroxyquinolines along with 3-bromo- and 3-chloroquinolin-6,8-diols were prepared and tested for antifungal activity against six fungi (Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, Trichophyton mentagrophytes) in Sabouraud dextrose broth. Compounds with chlorine in the 3 position were generally more fungitoxic than the corresponding analogues with bromine. 6-Bromo-3-chloro-8-quinolinol inhibited four fungi at levels below 1 μg/ml and A. niger and M. cirinelloides at 2 μg/ml each

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Antifungal Activity Of Halophenols And Halonitrophenols / H. Gershon, D. D. Clarke, And M. Gershon Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 1995

Antifungal Activity Of Halophenols And Halonitrophenols / H. Gershon, D. D. Clarke, And M. Gershon Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

Thirty one compounds (phenol; its 12 possible monohalo analogues; 18 nitrophenols (2- and 4-nitrophenols, 4-, 5-, and 6-halo-2-nitrophenols, 3-halo-4-nitrophenols)) were tested for antifungal activity against six fungi (A. niger, A. oryzae, M. verrucaria, T. viride, M. cirinelloides, and T. mentagrophytes) in Sabouraud dextrose broth. The two most fungitoxic compounds of those studied were 5-fluoro- and 5-iodo-2-nitrophenols which inhibited all the fungi at concentrations under 10 μg/ml. 6-Iodo-2-nitrophenol inhibited five fungi at a concentration below 10 μg/ml and M. cirinelloides at 10- 100 μg/ ml

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Substituted 8-Quinolinols: Halo, Nitro, And Sulfonic Acids / Herman Gershon, Donald D. Clarke, And Muriel Gershon Department Of Chemistry, Fordham University, Bronx, New York 10458 U.S.A., New York Botanical Garden, Bronx, New York 10458, U.S.A., Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 1995

Substituted 8-Quinolinols: Halo, Nitro, And Sulfonic Acids / Herman Gershon, Donald D. Clarke, And Muriel Gershon Department Of Chemistry, Fordham University, Bronx, New York 10458 U.S.A., New York Botanical Garden, Bronx, New York 10458, U.S.A., Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

Methods have been systematized for preparing substituted 8-quinolinols. The 5 and 7 positions are those available for electrophilic substitution. The entry position of the electrophile can be controlled by controlling the prototropic form of the 8-quinolinol. Under acidic conditions the 5 position is attacked first and under basic conditions the electrophile is directed to the 7 position. Iodination is the reverse. Regiospecificity also can be achieved by blocking the 5 or 7 position with sulfonic acid groups followed by addition of the electrophile and deblocking by acid hydrolysis, providing the new substituent is stable to acid hydrolysis. When compounds containing …

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Dissection Of An Antibody-Catalyzed Reaction, Jon D. Stewart, Joseph F. Krebs, Gary Siuzdak, Anthony J. Berdis, David B. Smithrud, Stephen J. Benkovic Aug 1994

Dissection Of An Antibody-Catalyzed Reaction, Jon D. Stewart, Joseph F. Krebs, Gary Siuzdak, Anthony J. Berdis, David B. Smithrud, Stephen J. Benkovic

Chemistry Faculty Publications

Antibody 43C9 accelerates the hydrolysis of a p-nitroanilide by a factor of 2.5 x 10(5) over the background rate in addition to catalyzing the hydrolysis of a series of aromatic esters. Since this represents one of the largest rate accelerations achieved with an antibody, we have undertaken a series of studies aimed at uncovering the catalytic mechanism of 43C9. The immunogen, a phosphonamidate, was designed to mimic the geometric and electronic characteristics of the tetrahedral intermediate that forms upon nucleophilic attack by hydroxide on the amide substrate. Further studies, however, revealed that the catalytic mechanism is more complex and involves …

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Use Of Pyocin To Select A Haemophilus Ducreyi Variant Defective In Lipooligosaccharide Biosynthesis, A A. Campagnari, R Karalus, M A. Apicella, William Melaugh, A J. Lesse, B W. Gibson Jan 1994

Use Of Pyocin To Select A Haemophilus Ducreyi Variant Defective In Lipooligosaccharide Biosynthesis, A A. Campagnari, R Karalus, M A. Apicella, William Melaugh, A J. Lesse, B W. Gibson

Chemistry Faculty Publications

Haemophilus ducreyi, a cause of genital ulcer disease in developing countries, appears to facilitate the heterosexual transmission of the human immunodeficiency virus in Africa. Despite an increase in studies of this gram-negative human pathogen, little is known about the pathogenesis of chancroid. Our studies have shown that the lipooligosaccharides (LOS) of H. ducreyi may play an important role in ulcer formation. Monoclonal antibody and mass spectrometric analyses identified a terminal trisaccharide present on H. ducreyi LOS that is immunochemically similar to human paragloboside. This epitope is present on the LOS of Neisseria gonorrhoeae, and it may be the site of …

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Evidence Of Steric Factors In The Fungitoxic Mechanism Of 8-Quinolinol And Its 2-, 3-, 4-, 5-, 6- And 7-Chloro And Bromo Analogues / Herman Gershon, Donald D. Clarke, And Muriel Gershon Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 1994

Evidence Of Steric Factors In The Fungitoxic Mechanism Of 8-Quinolinol And Its 2-, 3-, 4-, 5-, 6- And 7-Chloro And Bromo Analogues / Herman Gershon, Donald D. Clarke, And Muriel Gershon Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

A study was made of the fungitoxicity of 2-, 3-, 4-, 5-, 6- and 7-chloro and bromo- 8-quinolinols against Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride and Trichophyton mentagrophytes in Sabouraud dextrose broth and in Yeast Nitrogen Base supplemented with 1% D-glucose and 0.088% L-asparagine. Based on the presence or absence of synergism between pairs of substituted 8-quinolinols and reversal or nonreversal of toxicity by L-cysteine or Nacetyl- L-cysteine, the following conclusions were reached: (1) substituents on the quinoline ring change the site(s) of action of the toxicant; (2) the sites of action of the 5-, 6-, and 7-chloro-8-quinolinols …

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Preparation And Fungitoxicity Of 3,6-Dichloro- And 3,6-Dibromo-8-Quinolinols / H. Gershon, D. D. Clarke, And M. Gershon Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 1994

Preparation And Fungitoxicity Of 3,6-Dichloro- And 3,6-Dibromo-8-Quinolinols / H. Gershon, D. D. Clarke, And M. Gershon Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

3,6-Dichloro- and 3,6-dibromo-8-quinolinols were prepared by direct halogenation of 8-nitroquinoline by N-halosuccinimide in acetic acid or by halogenation of the corresponding 6-halo-8-nitroquinoline prepared via a Skraup reaction. The nitro group was reduced to amino and the amine was hydrolyzed to the phenol in 70% sulfuric acid at 220 °C. The fungitoxicity of 3,6-dichloro- and 3,6-dibromo-8-quinolinols, as well as intermediates in their preparation, against Aspergillus niger, Aspergillus oryzae, Myrothecium verrucaria, Trichoderma viride, and Mucor cirinelloides was determined. 3,6-dichloro-8-quinolinol is the most fungitoxic analogue of this class of compounds observed to date

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The 2′-Phosphate Of Nadp Is Critical For Optimum Productive Binding To 6-Phosphogluconate Dehydrogenase From Candida Utilis, Anthony J. Berdis, Paul F. Cook Sep 1993

The 2′-Phosphate Of Nadp Is Critical For Optimum Productive Binding To 6-Phosphogluconate Dehydrogenase From Candida Utilis, Anthony J. Berdis, Paul F. Cook

Chemistry Faculty Publications

Initial velocity studies obtained with alternative dinucleotide substrates for the 6-phosphogluconate dehydrogenase reaction suggest that the 2′-phosphate is critical for the optimum productive binding of the dinucleotide substrate. Initial velocity patterns obtained by varying 6-phosphogluconate at different fixed levels of NAD are nearly parallel with apparent competitive substrate inhibition by 6-phosphogluconate at pH 7 and below but intersect to the left of the ordinate at pH 8 and above. Dead-end inhibition studies indicate that the mechanism is random at all pH values. Data are interpreted in terms of a random mechanism with marked antagonism in the binding of NAD and …

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Investigation Of The Structural Heterogeneity Of Lipooligosaccharides From Pathogenic Haemophilus And Neisseria Species And Of R-Type Lipopolysaccharides From Salmonella Typhimurium By Electrospray Mass Spectrometry, B W. Gibson, William Melaugh, Nancy J. Phillips, M A. Apicella, A A. Campagnari, J M. Griffiss Jan 1993

Investigation Of The Structural Heterogeneity Of Lipooligosaccharides From Pathogenic Haemophilus And Neisseria Species And Of R-Type Lipopolysaccharides From Salmonella Typhimurium By Electrospray Mass Spectrometry, B W. Gibson, William Melaugh, Nancy J. Phillips, M A. Apicella, A A. Campagnari, J M. Griffiss

Chemistry Faculty Publications

Heterogeneity in the lipooligosaccharides (LOS) of pathogenic Haemophilus and Neisseria species is evident from the multiplicity of components observed with electrophoretic analyses. Knowledge of the precise structures that make up these diverse LOS molecules is clearly the key to reaching an understanding of pathogenic processes such as phase variation and molecular mimicry. Except for a few cases, little is known about the specific structural features of LOS that underlie phase variation and molecular mimicry, partly because of the inherent difficulties in the structural elucidation of these complex glycolipids. In the lipopolysaccharides (LPS) from Salmonella typhimurium and Escherichia coli, rough, or …

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Reexamination Of The Thermolytic Rearrangement Of 4-Halophenyl Azides To 2-Aminophenols And Other Products / H. Gershon, D. D. Clarke, And M. Gershon, Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa, New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 1993

Reexamination Of The Thermolytic Rearrangement Of 4-Halophenyl Azides To 2-Aminophenols And Other Products / H. Gershon, D. D. Clarke, And M. Gershon, Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa, New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

The halogenation of derivatives of 2-aminophenol with N-chloro- and N-bromosuccinimides at ambient temperatures in acetic acid was studied. With the necessary compounds available, a reexamination of the thermolytic rearrangement of 2-halophenyl azides to 2-aminophenols and other products was undertaken. It is certain that the rearrangement of 4-halophenyl azides to 2-aminophenols occurs but the products identified in this study differ significantly from those reported previously by Suschitzky et al. (1963, 1966)

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Improved Syntheses Of Some Monochloro- And Monobromo-8-Quinolinols / Herman Gershon And Donald D. Clarke Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd Jan 1991

Improved Syntheses Of Some Monochloro- And Monobromo-8-Quinolinols / Herman Gershon And Donald D. Clarke Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd

Chemistry Faculty Publications

Procedures were developed for the preparation of the 2-, 3-, 4-, and 6-monosubstituted chloro and bromo 8-quinolinols which afforded greater yields and/or reduced the number of steps in the preparation. 100 MHz 1H-NMR spectra for the 12 possible monochloro and mono bromo analogues are given

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Fluoroacetate And Fluorocitrate: Mechanism Of Action / Donald D. Clarke, Donald Dudley Clarke Phd Jan 1991

Fluoroacetate And Fluorocitrate: Mechanism Of Action / Donald D. Clarke, Donald Dudley Clarke Phd

Chemistry Faculty Publications

The concept of lethal synthesis as suggested by Peters is reviewed in the light of the more recent work in this area. It is suggested that fluorocitrate is a "suicide" substrate for aconitase rather than a competitive inhibitor as originally suggested. The use of these substances to study glialneuronal relationships is considered

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Evidence Of Steric Factors In The Fungitoxic Mechanism Of 8-Quinolinol And Its 5- And 7-Halogenated Analogues / Herman Gershon, Donald D. Clarke, And Muriel Gershon, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 1991

Evidence Of Steric Factors In The Fungitoxic Mechanism Of 8-Quinolinol And Its 5- And 7-Halogenated Analogues / Herman Gershon, Donald D. Clarke, And Muriel Gershon, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

Antifungal studies were made of mixtures of minimal inhibitory concentrations (MICs) of 8-quinolinol and its 5- and 7-halo analogues against six fungi: Aspergillus niger, A. oryzae, Trichoderma viride, Myrothecium verrucaria, Mucor cirinelloides, and Trichophyton mentagrophytes. Mixtures of 8-quinolinol with 5- or 7-fluoro-8-quinolinol and of 5- and 7-fluoro-8-quinolinol showed additive activity, and their respective toxicities were reversed by L-cysteine. These results suggested a common mechanism of activity for the three toxicants. Potentiation of the fungitoxicity of mixtures of 8-quinolinol and its 5- and 7-chloro, bromo, and iodo analogues, as well as mixtures of 5- and 7-chloro, 5- and 7-bromo, and 5- …

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Some Diazinon Analogues Containing The 4-Trifluoromethyl Group / Herman Gershon, Donald D. Clarke, Anthony T. Grefig, And Thomas E. Anderson Boyce Thompson Institute For Plant Research At Cornell University, Ithaca, Ny 14853, U.S.A. Department Of Chemistry, Fordham University, Bronx, Ny 10458, U.S.A., Herman Gershon, Donald Dudley Clarke Phd, Anthony T. Grefig, Thomas E. Anderson Jan 1990

Some Diazinon Analogues Containing The 4-Trifluoromethyl Group / Herman Gershon, Donald D. Clarke, Anthony T. Grefig, And Thomas E. Anderson Boyce Thompson Institute For Plant Research At Cornell University, Ithaca, Ny 14853, U.S.A. Department Of Chemistry, Fordham University, Bronx, Ny 10458, U.S.A., Herman Gershon, Donald Dudley Clarke Phd, Anthony T. Grefig, Thomas E. Anderson

Chemistry Faculty Publications

Diazinon analogues were prepared containing trifluoromethyl in place of the 4-methyl group and methylthio (2a), amino (2b), dimethylamino (2c), methylphenylamino (2d), or isopropyl (2e) in position 2 of the pyrimidine ring. The most active analogue (2 b) was less than half as insecticidal as Diazinon

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Intermediary Metabolism / Donald D. Clarke, Abel L. Lajtha, And Howard S. Maker, Donald Dudley Clarke Phd, Abel L. Lajtha, Howard S. Maker Md Jan 1989

Intermediary Metabolism / Donald D. Clarke, Abel L. Lajtha, And Howard S. Maker, Donald Dudley Clarke Phd, Abel L. Lajtha, Howard S. Maker Md

Chemistry Faculty Publications

No abstract provided.

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Synergistic Antifungal Action Of 8-Quinoinol And Its Bischelate With Copper(Ii) And Mixed Ligand Chelates Composed Of Coper(Ii), 8-Quinolinol, And Aromatic Hydroxy Acids / Herman Gershon, Donald D., Clarke, And Muriel Gershon, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 1989

Synergistic Antifungal Action Of 8-Quinoinol And Its Bischelate With Copper(Ii) And Mixed Ligand Chelates Composed Of Coper(Ii), 8-Quinolinol, And Aromatic Hydroxy Acids / Herman Gershon, Donald D., Clarke, And Muriel Gershon, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

Antifungal studies were made of mixtures of minimal inhibitory concentrations (MICs) of 8-quinolinol and its bischelates with copper(II), zinc(II), and manganese(II) and with mixed ligand chelates composed of 8-quinolinol, copper(II) and a second ligand including salicylic acid, 3-hydroxy-2-naphthoic acid, 3,5-diiodosalicylic acid, and 4-bromo-3-hydroxy-2-naphthoic acid. Mixtures of the MICs of the bischelates of 8-quinolinol with copper(II) and zinc(II) and copper(II) and manganese(II), as well as 7-iodo-8-quinolinol and its bischelate with copper(II), and 8-quinolinol and 5-iodo-8-quinolinol were also studied against six fungi: Aspergillus niger, Aspergillus oryzae, Trichoderma viride, Myrothecium verrucaria, Mucor cirinelloides, and Trichophyton mentagrophytes. With the exceptions of the mixtures of …

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Studies Of Transketolase Abnormality In Alzheimer's Disease / Kwan-Fu Rex Sheu, Phd; Donald D. Clarke, Phd; Young-Tai Kim, Phd; John P. Blass, Md, Phd; Bradford J. Harding; Joseph Decicco, Kwan-Fu Rex Sheu, Donald Dudley Clarke Phd, Young-Tai Kim, John P. Blass Jan 1988

Studies Of Transketolase Abnormality In Alzheimer's Disease / Kwan-Fu Rex Sheu, Phd; Donald D. Clarke, Phd; Young-Tai Kim, Phd; John P. Blass, Md, Phd; Bradford J. Harding; Joseph Decicco, Kwan-Fu Rex Sheu, Donald Dudley Clarke Phd, Young-Tai Kim, John P. Blass

Chemistry Faculty Publications

The partially purified transketolase from each of eight well-nourished patients with Alzheimer's disease contained significantly less heat-stable component with a significantly longer half-life of heat inactivation than that from eight controls. Immunochemical studies utilizing antibodies to the purified human liver transketolase did not distinguish between red blood cell transketolases of patients with Alzheimer's disease and those of controls. However, three brains from patients with Alzheimer's disease that were deficient in transketolase activity lacked a 69-kilodalton form on immunoblots. Subtle structural abnormalities of transketolase appear to occur in a high proportion of patients with Alzheimer's disease

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Pyrimidines. 8. Chlorination Of 6-Methyluracil With Phosphorus Oxychloride In The Presence Of Trialkyamines / Herman Gershon [Ab], Anthony T. Grefig [A], And Donald D. Clarke [B] [A] Boyce Thompson Institute For Plant Research At Cornell University, Ithaca, New York 14853 [B] Department Of Chemistry, Fordham University, Bronx, New York 10458, Herman Gershon, Anthony T. Grefig, Donald Dudley Clarke Phd Jan 1987

Pyrimidines. 8. Chlorination Of 6-Methyluracil With Phosphorus Oxychloride In The Presence Of Trialkyamines / Herman Gershon [Ab], Anthony T. Grefig [A], And Donald D. Clarke [B] [A] Boyce Thompson Institute For Plant Research At Cornell University, Ithaca, New York 14853 [B] Department Of Chemistry, Fordham University, Bronx, New York 10458, Herman Gershon, Anthony T. Grefig, Donald Dudley Clarke Phd

Chemistry Faculty Publications

The effect of the tertiary amines triethyl, tri-n-propyl, and tri-n-butylamines on the chlorination of 6-methyluracil by phosphorus oxychloride was studied. A comparison with the reaction of preformed 2,4-dichloro-6-methylpyrimidine and triethylamine in toluene was made. The reaction in phosphorus oxychloride in the presence of triethylamine afforded low yields of 2-diethylamino derivative after short heating periods and high yields of the 2,4-bis(diethylamino) derivative after 188 hours of boiling. Heating the preformed 2,4-dichloro-6-methylpyrimidine in toluene in the presence of triethylamine yielded primarily the 2-diethylaminopyrimidine along with a small amount of the 4-diethylamino isomer. After 188 hours, the product mixture was composed of 87% …

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Pyrimidines. 9. Chlorination Of 6-Trifluoromethyluracil With Phosphorus Oxychloride In The Presence Of Trialkylamines / Herman Gershon [Ab], Anthony T. Grefig [A], And Donald D. Clarke [B] [A] Boyce Thompson Institute For Plant Research At Cornell University, Ithaca, New York 14853 [B] Department Of Chemistry, Fordham University, Bronx, New York 10458, Herman Gershon, Anthony T. Grefig, Donald Dudley Clarke Phd Jan 1987

Pyrimidines. 9. Chlorination Of 6-Trifluoromethyluracil With Phosphorus Oxychloride In The Presence Of Trialkylamines / Herman Gershon [Ab], Anthony T. Grefig [A], And Donald D. Clarke [B] [A] Boyce Thompson Institute For Plant Research At Cornell University, Ithaca, New York 14853 [B] Department Of Chemistry, Fordham University, Bronx, New York 10458, Herman Gershon, Anthony T. Grefig, Donald Dudley Clarke Phd

Chemistry Faculty Publications

Ring-chlorination of 6-trifluoromethyluracil in phosphorus oxychloride in the presence of triethyl, tri-npropyl, and tri-n-butylamines was studied with respect to by-product formation. Comparisons were made with the results obtained by treating the preformed chlorinated pyrimidine with triethyl amine in boiling toluene. Amination of chloropyrimidines by tertiary amines takes place by a Hofmann type reaction with substituent orientation generally in the 2 position of the ring. Yields of products depended on the base and reaction time. The rate of substitution in the 2 position is significantly enhanced by the presence of the trifluoromethyl group in the 6 position as compared with a …

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Acetylation Of Synaptosomal Protein: Effect Of Na+ / Arlene Colon, Soll Berl, And Donald D. Clarke, Arlene D. Colon, Soll Berl, Donald Dudley Clarke Phd Jan 1987

Acetylation Of Synaptosomal Protein: Effect Of Na+ / Arlene Colon, Soll Berl, And Donald D. Clarke, Arlene D. Colon, Soll Berl, Donald Dudley Clarke Phd

Chemistry Faculty Publications

In a previous study it was shown that the acetyl moiety can be incorporated into the protein of purified synaptosomes (1). This process was inhibited by veratridine and the inhibitory effect was counteracted by tetrodotoxin. This suggested that the flux ofNa +may be related to the acetylation process. We now report that in a sodium free medium the amount of acetylation is increased and the inhibitory effect of veratridine (veratrine) is no longer evident. The addition ofNa +leads to a decrease in acetylation in the presence of veratrine. The presence of scorpion toxin has an effect similar to that of …

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Purification And Characterization Of A Soluble And A Particulate Glutamate Dehydrogenase From Rat Brain / Arlene D. Colon, Andreas Plaitakis, Antonis Perakis, Soll Berl, And Donald D. Clarke Department Of Neurology, Mount Sinai School Of Medicine, New York, And Department Of Chemistry, Fordham University, Bronx, New York, U.S.A., Arlene D. Colon, Andreas Plaitakis, Antonis Perakis, Donald Dudley Clarke Phd Jan 1986

Purification And Characterization Of A Soluble And A Particulate Glutamate Dehydrogenase From Rat Brain / Arlene D. Colon, Andreas Plaitakis, Antonis Perakis, Soll Berl, And Donald D. Clarke Department Of Neurology, Mount Sinai School Of Medicine, New York, And Department Of Chemistry, Fordham University, Bronx, New York, U.S.A., Arlene D. Colon, Andreas Plaitakis, Antonis Perakis, Donald Dudley Clarke Phd

Chemistry Faculty Publications

Glutamate dehydrogenase (GDH) activity was determined in high-speed fractions (1 00,000 g for 60 min) obtained from whole rat brain homogenates after removal of a low-speed pellet (480 g for 10 min). Approximately 60% of the high-speed GDH activity was particulate (associated with membrane) and the remaining was soluble (probably of mitochondrial matrix origin). Most of the particulate GDH activity resisted extraction by several commonly used detergents, high concentration of salt, and sonication; however, it was largely extractable with the cationic detergent cetyltrimethylammonium bromide (CTAB) in hypotonic buffer solution. The two GDH activities were purified using a combination of hydrophobic …

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The Subcellular Localization Of Glutamate Dehydrogenase (Gdh): Is Gdh A Marker For Mitochondria In Brain? / James C. K. Lai, Kwan-Fu Rex Sheu, Young Tai Kim, Donald D. Clarke, And John P. Blass Department Of Neurology, Cornell University Medical College And Altschul Laboratory For Dementia Research Burke Rehabilitation Center White Plains, Ny 10605 And Department Of Medicine Cornell University Medical College New York, Ny 10021, James C. K. Lai, Kwan-Fu Rex Sheu, Young Tai Kim, Donald Dudley Clarke Phd Jan 1986

The Subcellular Localization Of Glutamate Dehydrogenase (Gdh): Is Gdh A Marker For Mitochondria In Brain? / James C. K. Lai, Kwan-Fu Rex Sheu, Young Tai Kim, Donald D. Clarke, And John P. Blass Department Of Neurology, Cornell University Medical College And Altschul Laboratory For Dementia Research Burke Rehabilitation Center White Plains, Ny 10605 And Department Of Medicine Cornell University Medical College New York, Ny 10021, James C. K. Lai, Kwan-Fu Rex Sheu, Young Tai Kim, Donald Dudley Clarke Phd

Chemistry Faculty Publications

Glutamate dehydrogenase (GDH, EC 1.4.1.2) has long been used as a marker for mitochondria in brain and other tissues, despite reports indicating that GDH is also present in nuclei of liver and dorsal root ganglia. To examine whether GDH can be used as a marker to differentiate between mitochondria and nuclei in the brain, we have measured GDH by enzymatic activity and on immunoblots in rat brain mitochondria and nuclei which were highly enriched by density-gradient centrifugation methods. The activity of GDH was enriched in the nuclear fraction as well as in the mitochondrial fraction, while the activities of other …

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Acetylation-Deacetylation Of Synaptosomal Proteins: Effect Of Na+ / S. Berl, A. Colon And D. D. Clarke. Mt. Sinai School Of Medicine, New York, N.Y. 10029, Soll Berl, Arlene D. Colon, Donald Dudley Clarke Phd Jan 1985

Acetylation-Deacetylation Of Synaptosomal Proteins: Effect Of Na+ / S. Berl, A. Colon And D. D. Clarke. Mt. Sinai School Of Medicine, New York, N.Y. 10029, Soll Berl, Arlene D. Colon, Donald Dudley Clarke Phd

Chemistry Faculty Publications

Synaptosomes (S) when incubated with 3H-acetate (HA), are rapidly labeled. The perchloric acid (PCA) precipitable proteins contain most of the radioactivity probably as the acetyl moiety, which is released in a volatile form after acid or base hydrolysis (Berl et al., - J. Neurochem. 40:176, 1983). Much of the radioactivity was chased by addition of unlabeled acetate suggesting that the acetylation was reversible. Labeling was also decreased in the presence of veratridine/veratrine (V, 100uPt!) and this effect was prevented by tetrodotoxin (2uM). When Na was omitted from the incubation medium, the incorporation of (HA) was increased; however, the effect of …

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Potassium 1,3,3a,8a-Tetrahydro-3a,8a-Dihydroxy-2,8-Dioxoindeno[1,2-D]Imidazole-2-Ethanesulfonate, K+.C12h11n2o7s- / By D. D. Bray And D. D. Clarke Chemistry Department, Fordham University, Bronx, Nyew York 10458, Usa And N. Chatterjie And B. Sinha Institute For Basic Research In Development Disabilities, 1050 Forest Hill Road, Staten Island, New York 10314, Usa, Diana Bray, Donald Dudley Clarke Phd, Nithiananda Chatterjie, B. Sinha Jan 1984

Potassium 1,3,3a,8a-Tetrahydro-3a,8a-Dihydroxy-2,8-Dioxoindeno[1,2-D]Imidazole-2-Ethanesulfonate, K+.C12h11n2o7s- / By D. D. Bray And D. D. Clarke Chemistry Department, Fordham University, Bronx, Nyew York 10458, Usa And N. Chatterjie And B. Sinha Institute For Basic Research In Development Disabilities, 1050 Forest Hill Road, Staten Island, New York 10314, Usa, Diana Bray, Donald Dudley Clarke Phd, Nithiananda Chatterjie, B. Sinha

Chemistry Faculty Publications

Mr = 366·40, monoclinic, P2/c, Z = 4, a=6·195 (1), b= 17·701 (4), c= 1.2·864 (3)A, P= 116·25(2)0 , V=l387·8A3, Dm=1·74, Dx= 1·754 Mg m-3, CuKa, l = 1·5418 A, ,u = 5·07 mm-1, T= 298 K, F(OOO) = 752, R = 0·074 for 2091 observed independent intensity data. Crystals were prepared by reacting the K salt of ureidotaurine with ninhydrin in acid solution. The product shows that the unsubstituted N -of the ureidotaurine reacts with the central C of ninhydrin

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