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Articles 1 - 14 of 14
Full-Text Articles in Physical Sciences and Mathematics
A Control Switch For Prothrombinase: Characterization Of A Hirudin-Like Pentapeptide From The Cooh Terminus Of Factor Va Heavy Chain That Regulates The Rate And Pathway For Prothrombin Activation, Michael A. Bukys, Paul Y. Kim, Michael E. Nesheim, Michael Kalafatis
A Control Switch For Prothrombinase: Characterization Of A Hirudin-Like Pentapeptide From The Cooh Terminus Of Factor Va Heavy Chain That Regulates The Rate And Pathway For Prothrombin Activation, Michael A. Bukys, Paul Y. Kim, Michael E. Nesheim, Michael Kalafatis
Chemistry Faculty Publications
Membrane-bound factor Xa alone catalyzes prothrombin activation following initial cleavage at Arg(271) and prethrombin 2 formation (pre2 pathway). Factor Va directs prothrombin activation by factor Xa through the meizothrombin pathway, characterized by initial cleavage at Arg(320) (meizo pathway). We have shown previously that a pentapeptide encompassing amino acid sequence 695-699 from the COOH terminus of the heavy chain of factor Va (Asp-Tyr-Asp-Tyr-Gln, DYDYQ) inhibits prothrombin activation by prothrombinase in a competitive manner with respect to substrate. To understand the mechanism of inhibition of thrombin formation by DYDYQ, we have studied prothrombin activation by gel electrophoresis. Titration of plasma-derived prothrombin activation …
(E,E)-1,3-Bis[9,10-Dihydro-9-Nitro-10-(TrinitroMethYl)-9-AnthrYl]Propane, Mustafa Arslan, Erol Asker, John Masnovi, Ronald J. Baker
(E,E)-1,3-Bis[9,10-Dihydro-9-Nitro-10-(TrinitroMethYl)-9-AnthrYl]Propane, Mustafa Arslan, Erol Asker, John Masnovi, Ronald J. Baker
Chemistry Faculty Publications
The title compound, C33H24N8O16, was obtained as a product of the photoreaction between 1,3-di-9-anthrylpropane and tetranitromethane. The molecule occupies a special position on a twofold axis. The trinitromethyl and nitro substituents on the 9,10-dihydroacridine system are E oriented.
A 2:1 Complex Of 1,3-Bis(9h-Carbazol-9-Yl)Propane And TetraChloro-P-Benzoquinone (P-Chloranil), Mustafa Arslan, Randolph B. Krafcik, John Masnovi, Ronald J. Baker
A 2:1 Complex Of 1,3-Bis(9h-Carbazol-9-Yl)Propane And TetraChloro-P-Benzoquinone (P-Chloranil), Mustafa Arslan, Randolph B. Krafcik, John Masnovi, Ronald J. Baker
Chemistry Faculty Publications
In the title electron donor–acceptor complex, C27H22N2·0.5C6Cl4O2, the p-chloranil molecule lies on a crystallographic inversion center, which is located at the center of the benzene ring. In the crystal structure, one p-chloranil molecule lies above and below the central rings of each donor group of two neighboring 1,3-bis(9H-carbazol-9-yl)propane molecules, with a ring-centroid separation of 3.444 (1) Å. The angle between the planes of the stacking rings of the carbazole and p-chloranil molecules is 3.4 (2)°.
Rnase L: Its Biological Roles And Regulation, Shu Ling Liang, David Quirk, Aimin Zhou
Rnase L: Its Biological Roles And Regulation, Shu Ling Liang, David Quirk, Aimin Zhou
Chemistry Faculty Publications
2'-5'oligoadenylate-dependent ribonuclease L (RNase L) is one of the key enzymes involved in the function of interferons (IFNs), a family of cytokines participating in innate immunity against viruses and other microbial pathogens. Upon binding with its activator, 5'-phosphorylated, 2'-5' linked oligoadenylates (2-5A), RNase L degrades single-stranded viral and cellular RNAs and thus plays an important role in the antiviral and antiproliferative functions of IFNs. In recent years, evidence has revealed that RNase L displays a broad range of biological roles which are summarized in this review.
10,10′-Dinitro-10,10′-(Butane-1,4-DiYl)Dianthracen-9(10h)-One, Mustafa Arslan, Erol Asker, John Masnovi, Ronald J. Baker
10,10′-Dinitro-10,10′-(Butane-1,4-DiYl)Dianthracen-9(10h)-One, Mustafa Arslan, Erol Asker, John Masnovi, Ronald J. Baker
Chemistry Faculty Publications
The title compound, C32H24N2O6, was obtained as the decomposition product of (E,E)-1,4-bis[9,10-dihydro-9-nitro-10-(trinitromethyl)-9-anthryl]butane, which was synthesized via a photochemical reaction of 1,4-bis(9-anthryl)butane with tetranitromethane. The asymmetric unit contains one half-molecule; the complete molecule is generated by a center of inversion. The crystal packing is determined mainly by intermolecular C—H⋯O interactions.
The Structural Integrity Of Anion Binding Exosite I Of Thrombin Is Required And Sufficient For Timely Cleavage And Activation Of Factor V And Factor Viii, Michael A. Bukys, Tivadar Orban, Paul Y. Kim, Daniel O. Beck, Michael E. Nesheim, Michael Kalafatis
The Structural Integrity Of Anion Binding Exosite I Of Thrombin Is Required And Sufficient For Timely Cleavage And Activation Of Factor V And Factor Viii, Michael A. Bukys, Tivadar Orban, Paul Y. Kim, Daniel O. Beck, Michael E. Nesheim, Michael Kalafatis
Chemistry Faculty Publications
Alpha-thrombin has two separate electropositive binding exosites (anion binding exosite I, ABE-I and anion binding exosite II, ABE-II) that are involved in substrate tethering necessary for efficient catalysis. Alpha-thrombin catalyzes the activation of factor V and factor VIII following discrete proteolytic cleavages. Requirement for both anion binding exosites of the enzyme has been suggested for the activation of both procofactors by alpha-thrombin. We have used plasma-derived alpha-thrombin, beta-thrombin (a thrombin molecule that has only ABE-II available), and a recombinant prothrombin molecule rMZ-II (R155A/R284A/R271A) that can only be cleaved at Arg(320) (resulting in an enzymatically active molecule that has only ABE-I …
Numerical Simulation And Graphical Analysis Of In Vitro Benign Tumor Growth: Application Of Single-Particle State Bosonic Matter Equation With Length Scaling, Pradip K. Biswas, Jiansen Niu, Tobias Frederico, Valentin Gogonea
Numerical Simulation And Graphical Analysis Of In Vitro Benign Tumor Growth: Application Of Single-Particle State Bosonic Matter Equation With Length Scaling, Pradip K. Biswas, Jiansen Niu, Tobias Frederico, Valentin Gogonea
Chemistry Faculty Publications
We describe the application of a non-linear single-particle state bosonic condensate equation to simulate multicellular tumor growth by treating it as a coupling of two classical wave equations with real components. With one component representing the amplitude of the cells in their volume growth phase and the other representing the amplitude of the cells in their proliferation or mitosis phase, the two components of the coupled equation feed each other during the time evolution and are coupled together through diffusion and other linear and non-linear terms. The features of quiescent and necrotic cells, which result from poor nutrient diffusion into …
10,10′-Dinitro-10,10′-(Propane-1,3-DiYl)Di-10h-Anthracen-9-One, Mustafa Arslan, Erol Asker, John Masnovi, Ronald J. Baker
10,10′-Dinitro-10,10′-(Propane-1,3-DiYl)Di-10h-Anthracen-9-One, Mustafa Arslan, Erol Asker, John Masnovi, Ronald J. Baker
Chemistry Faculty Publications
The title compound, C31H22N2O6, was obtained as the decomposition product of (E,E)-1,3-bis[9,10-dihydro-9-nitro-10-(trinitromethyl)-9-anthryl]propane, which was synthesized via a photochemical reaction of 1,3-di-9-anthrylpropane with tetranitromethane. Intermolecular C—H⋯O interactions are the most prominent features of the crystal packing; no indications of any intermolecular π–π stacking were found.
Bis(9-EthylCarbazol-3-Yl)Ethane, Erol Asker, John Masnovi
Bis(9-EthylCarbazol-3-Yl)Ethane, Erol Asker, John Masnovi
Chemistry Faculty Publications
In the title compound, C30H28N2, each carbazole skeleton is essentially planar. The planes of the two carbazole ring systems are nearly parallel, with a dihedral angle of 2.33 (19)°. The crystal packing is stabilized only by van der Waals forces and weak C—H⋯π interactions.
9-Ethyl-3-(9h-9-EthylCarbazol-3-Yl)-4-Nitro-9h-Carbazole, Erol Asker, John Masnovi
9-Ethyl-3-(9h-9-EthylCarbazol-3-Yl)-4-Nitro-9h-Carbazole, Erol Asker, John Masnovi
Chemistry Faculty Publications
In the molecule of the title compound, C28H23N3O2, the nitro group is almost perpendicular to the carbazole ring to which it is attached. The crystal packing is determined by C—H⋯O and π–π interactions, where the nitrated carbazole ring of one molecule associates in a shifted parallel planar orientation with the centrosymmetrically related non-nitrated carbazole ring of a neighbouring molecule.
9,9′-Diethyl-3,3′-Di-9h-CarbazolYl, Erol Asker, John Masnovi
9,9′-Diethyl-3,3′-Di-9h-CarbazolYl, Erol Asker, John Masnovi
Chemistry Faculty Publications
In the title compound, C28H24N2, the carbazole ring systems are essentially planar to within 0.076 (3) Å. The dihedral angle between the planes of the ring systems is 40.38 (4)°. The contribution of intermolecular π–π interactions to the molecular stacking is observed.
Bis(9-EthylCarbazol-3-Yl)Methane, Erol Asker, John Masnovi
Bis(9-EthylCarbazol-3-Yl)Methane, Erol Asker, John Masnovi
Chemistry Faculty Publications
In the title compound, C29H26N2, the carbazole ring systems are essentially planar. There is no indication of π–π interactions in the crystal structure, adjacent carbazole groups being non-parallel.
Recent Developments Inthe Mechanistic Enzymology Of The Atp-Dependent Lon Protease From Escherichia Coli: Highlights From Kinetic Studies, Irene Lee, Anthony J. Berdis, Carolyn K. Suzuki
Recent Developments Inthe Mechanistic Enzymology Of The Atp-Dependent Lon Protease From Escherichia Coli: Highlights From Kinetic Studies, Irene Lee, Anthony J. Berdis, Carolyn K. Suzuki
Chemistry Faculty Publications
Lon protease, also known as protease La, is one of the simplest ATP-dependent proteases that plays vital roles in maintaining cellular functions by selectively eliminating misfolded, damaged and certain short-lived regulatory proteins. Although Lon is a homo-oligomer, each subunit of Lon contains both an ATPase and a protease active site. This relatively simple architecture compared to other hetero-oligomeric ATP-dependent proteases such as the proteasome makes Lon a useful paradigm for studying the mechanism of ATP-dependent proteolysis. In this article, we survey some recent developments in the mechanistic characterization of Lon with an emphasis on the utilization of pre-steady-state enzyme kinetic …
Fluorescent Analysis Of Translesion Dna Synthesis By Using A Novel, Non-Natural Nucleotide Analogue, Irene Lee, Anthony J. Berdis
Fluorescent Analysis Of Translesion Dna Synthesis By Using A Novel, Non-Natural Nucleotide Analogue, Irene Lee, Anthony J. Berdis
Chemistry Faculty Publications
The replication of damaged DNA is a promutagenic process that can lead to disease development. This report evaluates the dynamics of nucleotide incorporation opposite an abasic site, a commonly formed DNA lesion, by using two fluorescent nucleotide analogues, 2-aminopurine deoxyribose triphosphate (2-APTP) and 5-phenylindole deoxyribose triphosphate (5-PhITP). In both cases, the kinetics of incorporation were compared by using a 32 P-radiolabel extension assay versus a fluorescence-quenching assay. Although 2-APTP is efficiently incorporated opposite a templating nucleobase (thymine), the kinetics for incorporation opposite an abasic site are significantly slower. The lower catalytic efficiency hinders its use as a probe to study …