Physical Sciences and Mathematics | Open Access Articles

Novel Chemical Preparative Route For Semiconducting Mose2 Thin Films, K. C. Mandal, O. Savadogo

Faculty Publications

No abstract provided.

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In Situ Infrared Evidence For The Electrochemical Incorporation Of Hydrogen Into Si And Ge, K. C. Mandal, F. Ozanam, J.-N. Chazalviel

Faculty Publications

No abstract provided.

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Rheology Of Aqueous Suspensions Of Polystyrene Latex Stabilized By Grafted Poly(Ethylene Oxide), Harry J. Ploehn, J. W. Goodwin

Faculty Publications

A water-soluble carbodiimide has been used to end-graft aminated poly (ethylene oxide)(PEO) chemically onto colloidal polystyrene particles. Two particle sizes (115 and 347 nm diameter) and two PEO molecular weights (112 000 and 615 000 g mol^–1) were combined to give suspensions with four different ratios of polymer layer thickness to particle radius. Electrophoresis demonstrated that the PEO was grafted, not just adsorbed. Dynamic light scattering showed that the adsorbed and grafted layers had similar structures and that non-ionic surfactant perturbed the PEO configurations. Steady shear and oscillatory rheometry indicated that long-ranged polymeric forces between particles governed the …

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Inulin-125I-Tyramine, An Improved Residualizing Label For Studies On Sites Of Catabolism Of Circulating Proteins, Janet L. Maxwell, John W. Baynes, Suzanne R. Thorpe

Faculty Publications

Residualizing labels for protein, such as dilactitol-125I-tyramine (125I-DLT) and cellobiitol-125I-tyramine, have been used to identify the tissue and cellular sites of catabolism of long-lived plasma proteins, such as albumin, immunoglobulins, and lipoproteins. The radioactive degradation products formed from labeled proteins are relatively large, hydrophilic, resistant to lysosomal hydrolases, and accumulate in lysosomes in the cells involved in degradation of the carrier protein. However, the gradual loss of the catabolites from cells (t1/2 approximately 2 days) has limited the usefulness of residualizing labels in studies on longer lived proteins. We describe here a higher molecular weight (Mr approximately 5000), more efficient …

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Oxidative Degradation Of Glucose Adducts To Protein: Formation Of 3-(NE-Lysino)-Lactic Acid From Model Compounds And Glycated Proteins, Mahtab U. Ahmed, John A. Dunn, Michael D. Walla, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

The chemistry of Maillard or browning reactions of glycated proteins is being studied in model systems in vitro in order to characterize potential reaction pathways and products in biological systems. In previous work with the Amadori rearrangement product N alpha-formyl-N epsilon-fructoselysine (fFL), an analog of glycated lysine residues in proteins, we showed that fFL was oxidatively cleaved between C-2 and C-3 of the carbohydrate chain to yield N epsilon-carboxymethyllysine (CML) and D-erythronic acid. We then detected CML in proteins glycated in vitro, as well as in human lens proteins and collagen in vivo (Ahmed, M. U., Thorpe, S. R., and …

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A Cytochemical Study Of The Transcriptional And Translational Regulation Of Nuclear Transition Protein 1 (Tp1), A Major Chromosomal Protein Of Mammalian Spermatids, Mohammad A. Heidaran, Richard M. Showman, Wilson Stephen Kistler

Faculty Publications

Immunocytochemical localization and in situ hybridization techniques were used to investigate the presence of spermatid nuclear transition protein 1 (TP1) and its mRNA during the various stages of spermatogenesis in the rat. A specific antiserum to TP1 was raised in a rabbit and used to show that TP1 is immunologically crossreactive among many mammals including humans. During spermatogenesis the protein appears in spermatids as they progress from step 12 to step 13, a period in which nuclear condensation is underway. The protein is lost during step 15. An asymmetric RNA probe generated from a TP1 cDNA clone identified TP1 mRNA …

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Observation Of An Oxygen Isotope Effect In Yba2Cu3O7, Kevin J. Leary, Hans Conrad Zur Loye, Steven W. Keller, Tanya A. Faltens, William K. Ham, James N. Michaels, Angelica M. Stacy

Faculty Publications

A small decrease in T_c of 0.3 K to 0.5 K is observed when as much as 90% of the ¹⁶O in YBa₂Cu₃O₇ is substituted with¹⁸O. This result is consistent with our observation that there is an oxygen isotope effect in La_1.85Sr_0.15CuO₄, but in contrast with previous reports that there is no isotope effect for YBa₂Cu₃O₇. This new result suggests that phonons play an important role in the electron-pairing mechanism in YBa₂Cu₃O₇.

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Observation Of An Isotope Shift In The Superconducting Transition Temperature Of La1.85Sr0.15Cuo4, Tanya A. Faltens, William K. Ham, Steven W. Keller, Kevin J. Leary, James N. Michaels, Angelica M. Stacy, Hans Conrad Zur Loye, Donald E. Morris, T W. Barbee Iii, Marvin L. Cohen, Cohen S. Hoen, A Zettl

Faculty Publications

An oxygen isotope shift is observed in superconducting La_1.85Sr_0.15CuO₄ when ¹⁸O is substituted partially for ¹⁶O; the superconducting transition temperature T_c is lowered by 0.3 to 1.0 K in different samples. We examine these results using conventioanl phonon-mediated BCS theory and conclude that, for La_1.85Sr_0.15CuO₄, phonons play an important role in the pairing mechanism.

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Search For Isotope Effect In Superconducting Y-Ba-Cu-O, L C. Bourne, M F. Crommie, A Zettl, Hans Conrad Zur Loye, S W. Keller, K L. Leary, Angelica M. Stacy, K J. Chang, Marvin L. Cohen, Donald E. Morris

Faculty Publications

An isotope effect has been searched for in the high-T_c, superconductor YBa₂Cu₃0_{7 —b} through substitution of ¹⁸0 for ¹⁶O. No shift in the superconducting transition temperature T, is observed by electrical resistivity or magnetic susceptibility measurements. We discuss the implications of this result for mechanisms of superconductivity in the high-T, oxides.

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Effect Of Phosphate On The Kinetics And Specificity Of Glycation Of Protein, Nancy G. Watkins, Carolyn I. Neglia-Fisher, Daniel G. Dyer, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

The glycation (nonenzymatic glycosylation) of several proteins was studied in various buffiner os rder to assess the effects of buffering ions on the kinetics and specificity of glycation of protein. Incubation of RNase with glucose in phosphate buffer resulted in inactivation of the enzyme because of preferential modification of lysine residues ino r near the activsei te. In contrast, in the cationic buffers, 3-(N-morpholino)propanesulfonic acid and 3-(N-tris(hydroxymethyl)rnethylamino)- 2-hydroxypropanesulfonica cid, the kineticso f glycation of RNase were decreased 2- to 3-fold, there was a decrease in glycation of active site versus peripheral lysines, and the enzyme was resistant to inactivation by …

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Identification Of Fibroblasts As A Major Site Of Albumin Catabolism In Peripheral Tissues, Jeffrey L. Strobel, Susan G. Cady, Thomas K. Borg, Louis Terracio, John W. Baynes, Suzanne R. Thorpe

Faculty Publications

Rat serum albumin has been labeledw ith dilactitollZ5I- tyramine,( 12‘I-DLT) a radioactive tracer which remains entrappedw ithin lysosomes following cellular uptake and degradation of the carrier protein. Similar kinetics of clearance from the rat circulation were observed for albumin labeled conventionally with lZsI or 12‘I-DLT-albumin, both proteinhsa ving circulating half-lives of -2.2 days. In contrast, the recovery of whole body radioactivity had half-lives of -2.2 and 5.1 days, respectively, for the two protein preparations, indicating substantial retention of degradation products derived from catabolism of ”‘I-DLT-albumin. Measurement of total and acid-soluble radioactivity in tissues 2 or 4 days after injection of …

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Identification Of N Epsilon-Carboxymethyllysine As A Degradation Product Of Fructoselysine In Glycated Protein, Mahtab U. Ahmed, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

The chemistry of Maillard or browning reactionosf glycated proteins was studied using the model compound, Nu-formyl-W-fructoselysine(f FL), an analog of glycated lysine residues in protein. Incubation of fFL (15 mM) at physiological pH and temperature in 0.2 M phosphate buffer resulted in formation of lVcarboxymethyllysine (CML) in about 40% yield after 15 days. CML was formed by oxidative cleavage of fFL between C-2 and C-3 of the carbohydrate chain and erythronic acid (EA) was identified a s , the split product formed in the reaction. Neither CML nor EA was formed from fFL under a nitrogen atmosphere. The rate of …

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Glycation Of Amino Groups In Protein, Nancy G. Watkins, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Ribonuclease A has been used as a model protein for studying the specificity of glycation of amino groups in protein under physiological conditions (phosphate buffer, pH 7.4, 37 “C). Incubation of RNase with glucose led to an enhanced rate of inactivation of the enzyme relative to the rate of modification of lysine residues, suggesting preferential modification of active site lysine residues. Sites of glycation of RNase were identified by amino acid analysis of tryptic peptides isolated by reverse-phase high pressure liquid chromatography and phenylboronate affinity chromatography. Schiff base adducts were trapped with Na- BH&N and the a-amino group of Lys-1 …

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Characterization Of Glycated Proteins By 13C Nmr Spectroscopy, Carolyn I. Neglia, Helga J. Cohen, Albert R. Garber, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

13C NMR spectroscopy has been used to characterize Amadori (ketoamine) adducts formed by reaction of [2-13C]glucose with free amino groups of protein. The spectra of glycated proteins were acquired in phosphate buffer at pH 7.4 and were interpreted by reference to the spectra of model compounds, N alpha-formyl-N epsilon-fructose-lysine and glycated poly-L-lysine (GlcPLL). The anomeric carbon region of the spectrum (approximately 90-105 ppm) of glycated cytochrome c was superimposable on that of N alpha-formyl-N epsilon-fructose-lysine, and contained three peaks characteristic of the alpha- and beta-furanose and beta-pyranose anomers of Amadori adducts to peripheral lysine residues on protein (pK alpha approximately …

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13C Nmr Investigation Of Nonenzymatic Glucosylation Of Protein, Carolyn I. Neglia, Helga J. Cohen, Albert R. Garber, Paul D. Ellis, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Nonenzymatic glucosylation of protein is initiated by the reversible condensation of glucose in its open chain form with the amino groups on the protein. The initial product is an aldimine (Schiff base) which cyclizes to the glycosylamine derivative. The aldimine can undergo a slow Amadori rearrangement to yield the relatively stable ketoamine adduct which is structurally analogous to fructose. 13C NMR has been used to characterize these early products of nonenzymatic glucosylation, using RNase A as a model protein. C-1 of the beta-pyranose anomer of the glycosylamine was identified at 88.8 ppm in the spectrum of RNase glucosylated approximately 1:1 …

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Nonenzymatic Glucosylation And Glucose-Dependent Cross-Linking Of Protein, Albert S. Eble, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

A model system using RNase A has been established for studying the nonenzymatic glucosylation and glucose-dependent cross-linking of protein (Maillard reaction) under physiological conditions in vitro. The rate of glucosylation of RNase was first order in glucose. Glucosylation was accompanied by a comparable decrease in primary amino groups in the protein and lysine recoverable by amino acid analysis. Analysis of glucosylation reaction mixtures by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of mercaptoethanol revealed the time-dependent formation of RNase dimer and trimer. The polymerization reaction was mixed order with respect to glucose concentration, but was approximately first order with …

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Nonenzymatic Glucosylation Of Rat Albumin: Studies In Vitro And In Vivo, James F. Day, Robert W. Thornburg, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Incubation of rat serum with D-glucose in vitro resulted in nonenzymatic glucosylation of serum proteins. Analysis of freshly isolated rat albumin by ion exchange chromatography indicated that the glucosylated albumin accounts for 6.7.+-. 0.9% of total albumin in normal rat serum. Glucosylation of rat albumin in vitro was 1st order with respect to glucose and albumin concentrations and occurs primarily (> 90%) at intrachain lysine residues. Kinetic analysis and inhibition of glucosylation by aspirin suggest that 1 reactive lysine residue is the primary site of glucosylation. Less than 5% of the radioactivity from glucosyl-albumin was released as glucose or mannose …

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Enhanced Nonenzymatic Glucosylation Of Human Serum Albumin In Diabetes Mellitus, C. Earl Guthrow, Mary Ann Morris, James F. Day, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Use of an ion exchange chromatographic method and a colorimetric method with thiobarbituric acid showed that levels of nonenzymatically glucosylated serum albumin were increased in patients with poorly controlled diabetes mellitus compared to controls. The two methods correlated well (r = 0.99) and clearly discriminated between normal and poorly controlled diabetic populations. The levels of glycosylated hemoglobin were also measured in both populations. Several patients apparently in good control based on glycosylated hemoglobin measurements were found to have increased levels of glycosylated albumin. Because albumin has a shorter circulating half-life than does the human erythrocyte, the plasma concentration of glucosylated …

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Nonenzymatically Glucosylated Albumin: In Vitro Preparation And Isolation From Normal Human Serum, James F. Day, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Incubation of human serum with D-[6-3H]glucose resulted in the gradual accumulation of radioactivity in acid-precipitable material. Upon chromatography on Sephadex G-200, radioactivity was found associated with each of the major molecular weight classes of serum protein. Purified human serum albumin was also glucosylated in vitro upon exposure to D-[6-3H]glucose in phosphate-buffered saline. The glucosylated and unmodified albumins were separated by ion exchange chromatography. The physiological significance of these observations in vitro was confirmed by the isolation and quantitation of glucosylated albumin from normal human serum. Glucosylated albumin represents approximately 6 to 15% of total serum albumin in normal adults. The …

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[3H]‑Raffinose, A Novel Radioactive Label For Determining Organ Sites Of Catabolism Of Proteins In The Circulation, Jonathon Van Zile, Lee A. Henderson, John W. Baynes, Suzanne R. Thorpe

Faculty Publications

The primary tissue sites of catabolism of plasma proteins with long circulating half-lives are unknown. It has been difficult to identify these sites because plasma proteins are delivered to tissues at relatively slow rates but are rapidly degraded intracellularly within lysosomes. Therefore, a tracer attached to protein is lost from the site of uptake before an amount sufficient for quantitation can accumulate. We hypothesized that sucrose (Glupal-2 /3Fruf) would be a useful label to circumvent this difficulty because of the stability of sucrose in lysosomes; and thus, sucrose should remain in tissue long after the protein to which it was …

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Effect Of Glycosylation On The In Vivo Circulating Half-Life Of Ribonuclease, John W. Baynes, Finn Wold

Faculty Publications

The circulating half-lives of the four isozymes of bovine pancreatic ribonuclease (RNases A, B, C, and D) have been determined in normal and in nephrectomized rats. The isozymes differ only in their glycosyl content. While A contains no sugars, B has a simple oligosaccharide (GlcNAc, Man,+), and C and D each have a complex oligosaccharide (GlcNAc, Man,., Gal, Fuc NeuAc%, and GlcNAc, Mans Gal, Fuc NeuAc,, respectively) attached to Asn-34 of the polypeptide chain. All four isozymes were cleared rapidly in normal rats (t,,, = 2 to 3 min), as expected on the basis of the established role of the …

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The Role Of A Dolichol-Oligosaccharide As An Intermediate In Glycoprotein Biosynthesis, An-Fei Hsu, John W. Baynes, Edward C. Heath

Faculty Publications

Incubation of mouse myeloma microsomes with GDP-[(14)C]mannose results in the biosynthesis of [(14)C]mannose phosphoryl dolichol [Baynes, J. W., Hsu, A.-F. & Heath, E. C. (1973) J. Biol. Chem. 248, 5693-5704] and a [(14)C]mannose- and N-acetylglucosamine (GlcNAc)-containing oligosaccharide derivative of dolichol. Thus, [(14)C]mannose phosphoryl dolichol and [(14)C]mannose-labeled oligosaccharide pyrophosphoryl dolichol were isolated from incubation mixtures by solubilization in 2% (w/v) Triton X-100 and the lipids were separated from small molecules by gel filtration fractionation. After removal of radioactive protein from the preparation, the two lipid derivatives were separated quantitatively by fractionation on a concanavalin A-Sepharose column; [(14)C]mannose phosphoryl dolichol was not …

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The Role Of Mannosyl-Phosphoryl-Dihydropolyisoprenol In The Synthesis Of Mammalian Glycoproteins, John W. Baynes, An-Fei Hsu, Edward C. Heath

Faculty Publications

A mouse myeloma tumor was used as a model system to study the biochemical steps involved in the incorporation of mannose into glycoproteins. This tumor, MOPC-46B, synthesizes a K-type immunoglobulin light chain (K-46) which is a glycoprotein with a single oligosaccharide side chain containing mannose as one of its constituent sugars. MOPC-46B microsomal preparations contain enzymes which transfer mannose from the sugar nucleotide, GDPmannose, to endogenous lipid and protein acceptors. Formation of the mannolipid proceeds by the reversible transfer of mannose from GDP-mannose to an endogenous phospholipid. The mannolipid was purified and characterized by chemical methods and mass spectrometry as …

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Human Complement Protein C8: The “Hole” Story, James M. Sodetz

Journal of the South Carolina Academy of Science

No abstract provided.

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Full-Text Articles in Physical Sciences and Mathematics

Novel Chemical Preparative Route For Semiconducting Mose2 Thin Films, K. C. Mandal, O. Savadogo

Faculty Publications

In Situ Infrared Evidence For The Electrochemical Incorporation Of Hydrogen Into Si And Ge, K. C. Mandal, F. Ozanam, J.-N. Chazalviel

Faculty Publications

Rheology Of Aqueous Suspensions Of Polystyrene Latex Stabilized By Grafted Poly(Ethylene Oxide), Harry J. Ploehn, J. W. Goodwin

Faculty Publications

Inulin-125I-Tyramine, An Improved Residualizing Label For Studies On Sites Of Catabolism Of Circulating Proteins, Janet L. Maxwell, John W. Baynes, Suzanne R. Thorpe

Faculty Publications

Oxidative Degradation Of Glucose Adducts To Protein: Formation Of 3-(NE-Lysino)-Lactic Acid From Model Compounds And Glycated Proteins, Mahtab U. Ahmed, John A. Dunn, Michael D. Walla, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

A Cytochemical Study Of The Transcriptional And Translational Regulation Of Nuclear Transition Protein 1 (Tp1), A Major Chromosomal Protein Of Mammalian Spermatids, Mohammad A. Heidaran, Richard M. Showman, Wilson Stephen Kistler

Faculty Publications

Observation Of An Oxygen Isotope Effect In Yba2Cu3O7, Kevin J. Leary, Hans Conrad Zur Loye, Steven W. Keller, Tanya A. Faltens, William K. Ham, James N. Michaels, Angelica M. Stacy

Faculty Publications

Faculty Publications

Search For Isotope Effect In Superconducting Y-Ba-Cu-O, L C. Bourne, M F. Crommie, A Zettl, Hans Conrad Zur Loye, S W. Keller, K L. Leary, Angelica M. Stacy, K J. Chang, Marvin L. Cohen, Donald E. Morris

Faculty Publications

Effect Of Phosphate On The Kinetics And Specificity Of Glycation Of Protein, Nancy G. Watkins, Carolyn I. Neglia-Fisher, Daniel G. Dyer, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Identification Of Fibroblasts As A Major Site Of Albumin Catabolism In Peripheral Tissues, Jeffrey L. Strobel, Susan G. Cady, Thomas K. Borg, Louis Terracio, John W. Baynes, Suzanne R. Thorpe

Faculty Publications

Identification Of N Epsilon-Carboxymethyllysine As A Degradation Product Of Fructoselysine In Glycated Protein, Mahtab U. Ahmed, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Glycation Of Amino Groups In Protein, Nancy G. Watkins, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Characterization Of Glycated Proteins By 13C Nmr Spectroscopy, Carolyn I. Neglia, Helga J. Cohen, Albert R. Garber, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

13C Nmr Investigation Of Nonenzymatic Glucosylation Of Protein, Carolyn I. Neglia, Helga J. Cohen, Albert R. Garber, Paul D. Ellis, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Nonenzymatic Glucosylation And Glucose-Dependent Cross-Linking Of Protein, Albert S. Eble, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Nonenzymatic Glucosylation Of Rat Albumin: Studies In Vitro And In Vivo, James F. Day, Robert W. Thornburg, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Enhanced Nonenzymatic Glucosylation Of Human Serum Albumin In Diabetes Mellitus, C. Earl Guthrow, Mary Ann Morris, James F. Day, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Nonenzymatically Glucosylated Albumin: In Vitro Preparation And Isolation From Normal Human Serum, James F. Day, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

[3H]‑Raffinose, A Novel Radioactive Label For Determining Organ Sites Of Catabolism Of Proteins In The Circulation, Jonathon Van Zile, Lee A. Henderson, John W. Baynes, Suzanne R. Thorpe

Faculty Publications

Effect Of Glycosylation On The In Vivo Circulating Half-Life Of Ribonuclease, John W. Baynes, Finn Wold

Faculty Publications

The Role Of A Dolichol-Oligosaccharide As An Intermediate In Glycoprotein Biosynthesis, An-Fei Hsu, John W. Baynes, Edward C. Heath

Faculty Publications

The Role Of Mannosyl-Phosphoryl-Dihydropolyisoprenol In The Synthesis Of Mammalian Glycoproteins, John W. Baynes, An-Fei Hsu, Edward C. Heath

Faculty Publications

Human Complement Protein C8: The “Hole” Story, James M. Sodetz

Journal of the South Carolina Academy of Science