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D C Teller

Publications and source records attributed to D C Teller.

At least 55 records · Page 3Linked to original sources
PubMed1986

Molecular characterization of the sex steroid binding protein (SBP) of plasma. Re-examination of rabbit SBP and comparison with the human, macaque and baboon proteins.

Physico-chemical characterization of the sex steroid-binding protein, SBP, of rabbit plasma reveals that it is a dimer of mol. wt 85,800 composed of similar subunits of mol. wt 43,000. These data confirm our original proposal for a dimeric structure. The protein contains 9% carbohydrate, comprised of mannose, galactose, N-acetylglucosamine and sialic acid. It is devoid of N-acetylgalactosamine and fucose. The protein binds one molecule of 5 alpha-dihydrotestosterone per dimer with a Kd of 0.89 nM (12 degrees C). Comparison with the human, monkey and baboon SBPs indicates that all these proteins have the same dimeric molecular organization and exhibit microheterogeneity in SDS-PAGE and isoelectricfocusing. Rabbit SBP, however, contains less carbohydrate and has a higher polypeptide molecular weight than all the other SBPs. Spectrophotometric data also indicate that some tryptophan residues are in a different chemical environment than those in other SBPs. The observed microheterogeneity in all four SBP species is due for the most part to variable glycosylation of the subunit and variability at the amino-terminal region of the subunit. Combination of these and other phenomena will generate a significant number of isomeric forms of the SBP subunit which will then interact stoichiometrically to yield active dimeric SBP molecules. These differ slightly from each other depending upon the charge and size of the subunit comprising the dimeric structure, and will result in the observed microheterogeneity of pure SBP preparations. Based on these results along with more recent amino acid sequence data, we conclude that all four SBPs are dimers composed of identical polypeptide chains.

Amino Acid Sequence↗
PubMed1985

IgG rheumatoid factors and staphylococcal protein A bind to a common molecular site on IgG.

The antigenic determinant on the Fc region of human IgG for two IgG rheumatoid factors (IgG-RF) from patients with rheumatoid arthritis were investigated in detail. The RF did not interact with IgG fragments that contained the C gamma 2 or C gamma 3 region alone, but required the presence of both regions for binding. The RF binding to solid-phase IgG were poorly inhibited by the IgG3 subclass and strongly inhibited by staphylococcal protein A (SPA) (42 kD), and fragment D of SPA (7 kD), indicating that the binding site is most likely the same as the Ga antigenic determinant described for IgM-RF, and is in the same location as the site on IgG that binds SPA. pH titration studies of the RF binding to IgG indicated the involvement of histidine and lysine or tyrosine side chains. Chemical modification studies showed the histidines were involved on the Fc side of the interactions, and tyrosines were involved on both the antigenic and antibody sides of the interactions. Lysines were not involved. The above information, and the knowledge of the number and position in space of the amino acid residues involved in the C gamma 2-C gamma 3 interface region of IgG, the binding site for SPA, and the amino acid substitutions in IgG3 that account for its inability to bind protein A, allowed the identification of the site on IgG that bind IgG-RF. This binding site involves some of the same amino acid side chains, His 435, Tyr 436, and one or both His 433 and 310, and is in the same location as the site that binds SPA. The same site is likely to be a common antigenic determinant for other RF. Furthermore, the described molecular mimicry suggests a biological relationship between bacterial Fc-binding proteins and the production of RF in rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1985

Properties of an interphotoreceptor retinoid-binding protein from bovine retina.

Washes and extracts of frozen and fresh cattle retina contain a water-soluble high-molecular-weight, retinoid-binding protein that is distinct from three other retinoid-binding proteins previously isolated from this tissue. The protein can be purified to apparent homogeneity from retinal homogenates by a combination of gel filtration, lectin, and ion-exchange chromatography. Overestimation of the protein molecular weight was observed in several systems involving migration of the protein through a porous network. The approximate molecular weight obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 140,000, a value consistent with those reported by other laboratories. However, a more detailed analysis using the method of Ferguson revealed the protein to behave anomalously relative to several proteins used as sodium dodecyl sulfate-polyacrylamide gel electrophoresis standards. The apparent radius of the native protein, estimated from calibrated gel filtration, corresponded to a globular protein with a molecular weight of 240,000-280,000, suggesting that the protein was a dimer. However, when the molecular weight of native interphotoreceptor retinoid-binding protein (IRBP) was determined by a method with no shape dependence, sedimentation equilibrium, a value of 131,700 +/- 3,900 g/mol, was obtained. Sedimentation equilibrium in a dissociating solvent (6 M guanidine HCl) yielded a molecular weight of the smallest component of 120,100 +/- 2,300 g/mol. The similarity of values for the denatured and native molecular weight by sedimentation equilibrium demonstrates that the protein is a monomer. In further support of this, no evidence for a dimer was observed in cross-linking experiments with dimethyl suberimidate. The sedimentation coefficient (S0(20),w = 5.73 +/- 0.15 S) and molecular weight from sedimentation equilibrium were employed to calculate the frictional coefficient and Stokes radius of IRBP (f/f0 = 1.64, Rs = 55 A). The high value of f/f0 of the protein provides a reasonable explanation for the over-estimation of the molecular weight of native IRBP on gel filtration. Approximately 2 mol of exogenous all-trans- or 11-cis-retinol were bound per mol of protein (131,000). Approximately 7% of the binding sites were saturated with endogenous ligand (11-cis-retinol, 88%; all-trans-retinol, 12%) following isolation from partially bleached cattle eyes.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1985

Fc intermediate (Fci), a papain-generated fragment of human IgG, intermediate in charge, molecular weight and cleavage between the Fc and Fc' fragments of IgG.

Fc intermediate (Fci) is a papain-generated fragment of human IgG which is intermediate in charge, mol. wt and state of cleavage between the Fc and Fc' fragments of IgG. It is composed of two polypeptide chains of unequal mol. wt held together by non-covalent bonds between the C gamma 3 regions. The larger polypeptide chain has both a C gamma 2 and C gamma 3 domain and its N-terminus is at Leu 235 (60%) and Leu 234 (40%) (IgGl Eu numbering). The smaller polypeptide chain is composed of a C gamma 3 domain with its N-terminus at Gly 341. The carboxy-termini obtained by carboxypeptidase digestion and by a computer program which determined the most probable sequences by fitting the amino acid compositions to the sequence of IgG Eu Fc were heterogeneous involving residues 440-446 for the large polypeptide chain and 429-436 for the small one. The calculated mol. wt of the large polypeptide chain was 26,183, assuming the N-terminus at Leu 234 and C-terminus at 446 and including the carbohydrate moiety. The calculated mol. wt for the small polypeptide chain was 10,682, with the N-terminus at 341 and assuming the C-terminus at 434, for a combined mol. wt of 36,865 for the Fci fragment. Sedimentation equilibrium ultracentrifugation of Fci under non-dissociating conditions showed an Mn of 36,200 +/- 1200, an Mw of 36,400 +/- 600 and an Mz of 37,000 +/- 300 g/mole. The best yields of Fc were obtained with a 6-hr digestion and the best yields of Fcl and Fc' were obtained with digestion for 18 hr in phosphate buffer. Digestion in Tris buffer for 18 hr gave results similar to the 18-hr digestion in phosphate buffer except the yields of Fc' were less. This fragment may be useful for exploring biological functions of human IgG Fc. In addition, some Fc fragments obtained by papain digestion of human IgG either in phosphate or Tris buffer are not covalently bonded and are probably cleaved on the carboxy-terminal side of the interchain disulfide bonds at Leu 234 or Leu 235, the N-termini for the large polypeptide chain of Fci. This indicates that, if disulfide bonded Fc fragments are needed, gel filtration under dissociating conditions will be necessary to remove non-covalently bonded Fc.

Amino Acid Sequence↗
PubMed1984

Separation of peptides on a polystyrene resin column.

A high-performance liquid chromatographic column of porous spherical polystyrene--divinylbenzene copolymer (Hamilton PRP-1) was found to be useful for reversed-phase resolution of a wide range of peptides. Recoveries and resolution were comparable with those from more widely used alkyl silica-based columns. Tests involving more than 40 peptides, ranging from 2 to 34 residues, and 3 proteins, indicated wide applicability of this column. The retention times of peptides of known composition are predicted. The stability of the resin at high pH permits protocols of separation involving successive chromatograms at widely different pH values, and offers a second dimension to the resolving power of a single column.

Amino Acids↗
PubMed1984

Self-associating IgG rheumatoid factors in MRL/l autoimmune mice.

Previous work has shown that the intermediate complexes isolated from the plasma of patients with rheumatoid arthritis are composed of self-associating IgG rheumatoid factors. Mice of the MRL/l strain develop spontaneous autoimmune disease with arthritis that is pathologically similar to human rheumatoid arthritis. Also, the sera of MRL/l mice contain autoantibodies to nuclear antigens as well as IgM and IgG rheumatoid factors. The present studies were done to determine if the IgG rheumatoid factors isolated from these mice undergo self-association. MRL/l mouse sera were categorized into groups A and B based on serum-serum precipitin interactions. Thirteen of 13 MRL/l mice sera examined contained intermediate complexes sedimenting between the 6.6S and 19S components of normal serum by sedimentation velocity ultracentrifugation. There were no differences in the level of intermediate complexes between groups A and B. IgG rheumatoid factors were isolated from the sera of 9 other mice. Upon sedimentation equilibrium ultracentrifugation, these rheumatoid factors underwent concentration-dependent self-association similar to that described for human self-associating IgG rheumatoid factors, although the precise stoichiometry of self-association could not be determined. The IgG rheumatoid factors from group B had higher energies of self-interaction than those from group A. These studies provide additional evidence that MRL/l mice may be the best available animal model for the study of human rheumatoid arthritis.

Animals↗
PubMed1983

Dynamic aspects of insulin action: synchronization of oscillatory glycolysis in isolated perifused rat fat cells by insulin and hydrogen peroxide.

Glucose oxidation to CO2 was investigated in isolated perifused rat epididymal fat cells. Insulin stimulated rates of oxidation up to 30-fold. Multiple pulses of insulin or prolonged perifusion with the hormone led to a time-dependent desensitization of the cells. The action of insulin could be mimicked by H2O2. Reversal of H2O2 effects was associated with a damped oscillation of large initial amplitude. Initiation of perifusion with insulin induced rates of glucose oxidation that oscillated around a mean elevated rate with an amplitude of about +/- 4% of the mean, significantly larger than the measurement error. Basal rates did not show clear oscillations. The oscillations after insulin had a statistically significant period of around 14 min. The results were the same with C1- or C6-labeled glucose and occurred in the presence of both 0.275 and 5.5 mM glucose in the perifusion medium. The oscillations were interpreted as the result of insulin- or H2O2-induced synchronization of oscillatory glycolysis by individual fat cells. The similarity of the observed oscillatory period with the period of oscillatory insulin secretion by pancreatic beta cells suggests that oscillatory glycolysis may constitute the internal pacemaker for the latter process.

Adipose Tissue↗
PubMed1983

Homology of amino acid sequences of rat liver cathepsins B and H with that of papain.

The amino acid sequences of rat liver lysosomal thiol endopeptidases, cathepsins B and H, are presented and compared with that of the plant thiol protease papain. The 252-residue sequence of cathepsin B and the 220-residue sequence of cathepsin H were determined largely by automated Edman degradation of their intact polypeptide chains and of the two chains of each enzyme generated by limited proteolysis. Subfragments of the chains were produced by enzymatic digestion and by chemical cleavage of methionyl and tryptophanyl bonds. Comparison of the amino acid sequences of cathepsins B and H with each other and with that of papain demonstrates a striking homology among their primary structures. Sequence identity is extremely high in regions which, according to the three-dimensional structure of papain, constitute the catalytic site. The results not only reveal the first structural features of mammalian thiol endopeptidases but also provide insight into the evolutionary relationships among plant and mammalian thiol proteases.

Amino Acid Sequence↗
PubMed1982

Characterization of a phosphorylated form of the intermediate filament-aggregating protein filaggrin.

Filaggrin and a phosphorylated form of filaggrin, which has been shown by pulse-chase studies to be a precursor form of the protein [Dale, B. A., & Ling, S. Y. (1979) Biochemistry 18, 3539-3546], were compared for functional, biochemical, and physical properties. Filaggrin reacts with keratin filaments to form visible macrofibrils, unlike the precursor which does not. Biochemical and peptide-mapping studies suggest that the two proteins have similar, perhaps identical, amino acid sequences. The major differences between the two proteins are in molecular weight (precursor, 44 200 g/mol; filaggrin, 38 400 g/mol), the existence of oligomeric forms of the precursor, and the presence of phosphate in the precursor (15-20 mol/mol of protein). Phosphoserine was identified in the precursor, but neither phosphothreonine nor phosphotyrosine was observed. The results of proteolytic digests of [32P]phosphate-radiolabeled precursor show that the phosphate is unevenly distributed throughout the molecule and may be localized in approximately 30% of the precursor. A discrete localization of the phosphate in the precursor may block a specific keratin filament combining site and so prevent premature aggregation of these filaments during epidermal differentiation. It is suggested that a specific phosphatase is involved in the dephosphorylation, because several phosphatases of general specificity, including rat epidermal lysosomal acid phosphatase, did not catalyze this conversion.

Amino Acids↗
PubMed1981

Studies on the antigenic determinants in the self-association of IgG rheumatoid factor.

The number, location, and other characteristics of the antigenic determinants for self-association of IgG-rheumatoid factors (IgG-RF) were examined using the IgG-RF isolated from the plasma of one patient as a model system. Affinity chromatography was employed for isolation of the IgG-RF. Sedimentation equilibrium ultracentrifugation was used to study the various interactions. The antigenic valence of IgG-RF Fc, normal human Fc, and rabbit Fc fragments was two for the interaction with Fab fragments from IgG-RF, as might be expected from the molecular symmetry of IgG. The antigenic valence of intact normal IgG, however, was only one, indicating that when one of the available antigenic determinants interacted with the Fab fragment of IgG-RF, the other determinant becomes sterically inaccessible. Reduction and alkylation, known to increase the flexibility of the hinge region, did not alter the antigenic valence of IgG for Fab fragments of IgG-RF. The antigenic valence of IgG-RF in self-association could not be experimentally determined but must be two to permit the observed concentration-dependent further polymer formation of IgG-RF dimers. Unique antigenic determinants on the Fc fragments of IgG-RF were sought and not found, thus reaffirming the formation of two antigen-antibody bonds as the basis for dimerization of IgG-RF molecules. The pFc' and Fc' fragments, representing Cgamma3 domains of IgG, failed to show significant interaction with Fab fragments of IgG-RF, indicating that the antigenic determinants were not expressed by the Cgamma3 regions but are located either on Cgamma2 region or require intact Cgamma2 and Cgamma3 regions for expression. These conclusions were corroborated by the antigenic valence of one for the Fc(i) fragment, a new papain-generated intermediate fragment of Fc, composed of two intact Cgamma3 domains and one intact Cgamma2 domain. Normal IgG, because of its valence of one for interaction with IgG-RF, would effectively terminate further polymerization of IgG-RF dimers. This may well in part explain the finding of smaller IgG-RF complexes in the serum than in synovial fluid of patients with rheumatoid arthritis.

Alkylation↗
PubMed1981

Thermodynamics of concanavalin A dimer-tetramer self-association: sedimentation equilibrium studies.

The effects of temperature and pH on the reversible dimer-tetramer association of concanavalin A were studied by the high-speed sedimentation equilibrium technique. Both commercial and highly purified preparations of concanavalin A were used. Equilibrium constants were analyzed as a Wyman linked function by using truncated van't Hoff temperature dependence. In the concentration range 0.1-3.0 mg/mL, from 5 to 35 degrees C and between pH 5.5 and pH 7.5 at 0.5 M ionic strength, only dimer and tetramer species were present in both preparations. For purified concanavalin A, association constants ranged from 1.5 X 10(3) to 8.0 X 10(7) M-1. Constants for our commercial preparation were approximately 10-fold lower due to the decrease competency of some subunits to self-associate. From the fit of the Wyman model to the experimental data, delta G degree, delta H degree, delta S degree, and delta Cp degree were calculated for the association and association-linked ionization reactions. From the values of the ionization thermodynamic parameters, the association is governed by the ionization of a histidine side chain on each subunit, either histidine-51 or histidine-121. The association is characterized by large entropy (66.3 cal.mol-1.deg-1 at 25 degrees C) and heat capacity (-821 cal.mol-1.deg-1) changes in accordance with the large hydrophobic association surface observed in crystallographic studies [Reeke, G. N., Jr., Becker, J. W., & Edelman, G. M. (1975) J. Biol. Chem. 250, 1525-1547]. In addition, there is a large enthalpy change (10.4 kcal.mol-1 at 25 degrees C). We propose a model for the interaction based on a more detailed thermodynamic description than was obtained in an earlier, incomplete study [Huet, M., & Clavarie, J. M. (1978) Biochemistry 17, 236-241].

Concanavalin A↗
PubMed1981

Effects of saccharide and salt binding on dimer-tetramer equilibrium of concanavalin A.

The effect of the binding of saccharide ligands on the reversible dimer-tetramer equilibrium on concanavalin A was studied by the high-speed sedimentation equilibrium technique. Both commercial and highly purified fragment-free concanavalin A preparations were used. In the case of the fragment-free preparation, there was no effect of the binding of alpha-methyl mannoside or alpha-methyl glucoside at 35 degrees C and at a variety of conditions of pH and ionic strength. This implies no difference in ligand binding activity between dimeric and tetrameric Con A, in contrast to an earlier report [McKenzie, G. H., & Sawyer, W. H. (1973) J. Biol. Chem. 248, 549-556]. There was a profound effect in the case of the commercial preparation. Dimers that contain hydrolyzed subunits appear to be incompetent to self-associate in the presence of alpha-methyl mannoside or alpha-methyl glycoside, while alpha-methyl galactoside, which does not bind to Con A, had no effect. The effects of very high concentrations of CaCl2 (to 2.5 m) and NaCl (60 6.2 m) were also studied. The data were analyzed by an integrated form of the Tanford extension [Tanford, C. (1969) J. Mol. Biol. 39, 539-544] of the Wyman linked function theory, which includes preferential interactions with salt and water. The integrated form allows preferential interactions to be described as the sum of salt binding and water binding. The data were well described by salt binding alone; it was unnecessary to invoke any water binding effect. The CaCl2 data did indicate that one calcium per subunit of the dimer binds to a site that is buried in the tetramer. This suggests a site on the dimmer-dimer interface which is consistent with Reeke's identification of the protomers composing the solution dimer [Reeke, G. N., Jr., Becker, J. W., & Edelman, G. M. (1975) J. Biol. Chem. 250, 1525-1547].

Calcium↗
PubMed1981

Molecular properties and active form of nonspecific acid phosphatase from Schizosaccharomyces pombe.

Equilibrium sedimentation experiments of the native acid phosphatase indicate a dimer-tetramer dissociating nonequilibrating system with a dimer Mr = 180,000 g/mol. The hydrolysis of nitrophenylphosphate was used to determine the sedimentation coefficient of the active species. The s20,w value for the species which degrades nitrophenylphosphate is 13.52 +/- 0.46 S in 1% sucrose and 13.72 +/- 0.11 S in 1.3 M sodium chloride, corresponding to the Svedberg value of the tetramer species. Several lines of evidence are presented which, together with previous data, indicate that the Schizosaccharomyces pombe nonspecific acid phosphatase is composed of 4 identical or nearly identical polypeptide chains: a, equilibrium sedimentation analysis of the enzyme in denaturing agents indicates the presence of homogeneous material having Mr = 90,800 g/mol; b, digestion with carboxypeptidase A releases 0.82 mol of tyrosine/monomer molecular weight. Concomitant phosphatase inactivation occurred during the splitting off of the tyrosyl terminal residue. Furthermore, a unique NH2-terminal residue (histidine) was determined.

Acid Phosphatase↗
PubMed1981

Characterization of a class of cationic proteins that specifically interact with intermediate filaments.

We describe a class of cationic structural proteins that associate specifically with intermediate filaments (IF) but not with other types of cytoskeletal proteins. These proteins, for which the term filaggrin is introduced, are isolated from the stratum corneum of mammalian epidermis. They are species-distinct proteins; for example, rat and mouse filaggrin have different molecular weights and amino acid compositions, but are nevertheless chemically and functionally ver similar. They interact in vitro with the IF several different types of cells to form large fibers or macrofibrils in which many IF are highly aligned in parallel arrays. Stoichiometric analyses suggest that two molecules of filaggrin bind to each three-chain building block of the IF, possibly by ionic interactions with the coiled-coil alpha-helical regions of the IF.

Amino Acids↗