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J D Capra

Publications and source records attributed to J D Capra.

At least 199 records · Page 11Linked to original sources
PubMed1982

VH families in the antibody response to p-azophenylarsonate: correlation between serology and amino acid sequence.

Anti-arsonate hybridoma antibodies of A/J mice have been grouped into 3 VH families by amino acid sequence analysis. One of these, the 91A3 family, which includes all CRI-positive molecules and some CRI-negative molecules, has been serologically defined by the presence of a VH marker (91A3 marker). Although the 91A3 family of antibodies is present at low levels in preimmune A/J serum and represents a substantial component of the A/J response to p-azophenylarsonate, the 91A3 family has not been detected serologically in the anti-Ar response of any other inbred strain tested. Analysis of sera from AXC Igh recombinant mice maps the 91A3 marker to the left of Igh-Dex, consistent with the location of the VH genes controlling the arsonate CRI. These studies establish a serologic assay that detects all members of a family of anti-arsonate antibodies defined previously by primary sequence analysis. This assay makes it possible to monitor in its entirety the expression of the products of a single or closely related group of genes.

Amino Acid Sequence↗
PubMed1982

The human HLA-DR antigens are encoded by multiple beta-chain loci.

Monoclonal antibodies have been used to isolate and characterize human HLA-DR antigens from human B cell lines. Using sequential immunodepletion experiments, several subsets of DR antigens have been identified. Partial amino-terminal amino acid sequencing has identified these subsets as DR molecules with sequences homologous to the murine I-E alloantigens. In addition, sequence data provide evidence for primary structural differences in the DR beta-chains of two of the subsets. These results provide primary structural evidence for the presence of multiple DR beta-chain loci.

Amino Acid Sequence↗
PubMed1982

Structural and functional characterization of an incompletely processed form of murine C4 and Slp.

The properties of a 128,000-dalton polypeptide, corresponding to the uncleaved alpha- and gamma- chains of the fourth component of murine complement (C4), were studied. A fragment of similar size (137,000 daltons) from the structurally related sex-limited protein (Slp) was also found. These polypeptides have methylamine and iodoacetamide binding sites. suggesting that they, like the alpha-chains of C4 and Slp, possess an internal thiolester. In tryptic peptide map analysis, extensive homology is seen between the 128,000-dalton fragment and native C4 alpha- and gamma-chains. N-terminal sequences for this fragment and C4 alpha are identical, as are those for the 137,000-dalton Slp fragment and Slp alpha. Although the alpha-gamma fragment, like C4 alpha, undergoes denaturation-dependent autolytic cleavage, unlike C4 alpha, it cannot be cleaved by C1 This indicate that some of the properties of C4 do not require the native three-chain structure, whereas others do require it. These findings suggest that the alpha-gamma fragments represent an intermediate step in the processing of the C4 and Slp precursor polypeptides.

Animals↗
PubMed1981

Amino acid sequence of the variable regions of light chains from two idiotypically cross-reactive human IgM anti-gamma-globulins of the Wa group.

The amino acids sequences of the variable regions of the light chains derived from two idiotypically related human monoclonal rheumatoid factors are reported. The sequences were obtained through automated Edman degradations of the intact light chains, peptides generated from tryptic digests of citraconylated light chains, and peptides obtained from chymotryptic digestions of light chains. Comparison of the sequences suggests that the idiotypic determinant(s) many reside in the framework portions of the two chains or their J segments.

Amino Acid Sequence↗
PubMed1981

Amino acid sequence of the variable regions of heavy chains from two idiotypically cross-reactive human IgM anti-gamma-globulins of the Wa group.

The amino acid sequences of the variable regions of the heavy chains derived from two idiotypically related human monoclonal rheumatoid factors are reported. The sequences were obtained through automated Edman degradations of the intact, pyroglutamate aminopeptidase cleaved heavy chains and peptides produced from digestion of the pentameric IgM with CNBr. The peptides generated from the CNBr reaction were further digested by trypsin and the Staphylococcus aureus V8 protease. Comparisons of these sequences and those of the light chains from these molecules [Andrews, D. W., & Capra, J. D. (1981) Biochemistry (preceding paper in this issue)] suggest that the idiotypic determinant(s) in this system may reside in the framework portions of these molecules or in their J segments.

Amino Acid Sequence↗
PubMed1981

The use of reversed-phase high-performance liquid chromatography with radial compression for the analysis of peptide and protein mixtures.

This report describes the separation of peptide and protein mixtures on a C18- microparticulate support which was packed in a polyethylene cartridge and subjected to radial compression of ca. 2600 p.s.i. The purpose of the radial compression was to minimise inhomogeneities in the column packing, in particular in the region of the column wall and end fittings. The effectiveness of this new chromatographic system was demonstrated by the efficient separation of the following mixtures: the C-apolipoproteins isolated from human very low density lipoproteins; the polymorphs of apolipoprotein A-I; the tryptic fragments of apolipoprotein C-II; the complex mixture generated by partial proteolysis of apolipoprotein B; the tryptic fragments of 3H- and 14C-labelled beta-chain of murine IA alloantigen and the tryptic fragments of carboxymethylated lambda chain isolated from human immunoglobulin G. The separated peaks were identified by amino acid analysis, radioactivity counting and in the last example by amino acid sequence determination. The mobile phase consisted of 1% aqueous solution of triethylammonium phosphate, pH 3.2 with acetonitrile or isopropanol as the organic modifier.

Amino Acids↗
PubMed1981

Complete amino acid sequence of light chain variable regions derived from five monoclonal anti-p-azophenylarsonate antibodies differing with respect to a crossreactive idiotype.

The induced antibody response to the hapten p-azophenylarsonate in the A/J mouse has provided a model system for the detailed examination of a heritable crossreactive idiotype and its fine structural and serologic analysis. While earlier studies used to apparent homogeneity in the serum response for structural studies, a more complete understanding of the arsonate idiotypic system became possible with the development of monoclonal antibodies differing with respect to these determinants. Five monoclonal antibodies, four crossreactive idiotype positive and one crossreactive idiotype negative, were selected for complete amino acid sequence analysis. The sequences of the light chain variable regions of these molecules are presented here. The data indicate considerable sequence divergence of the monoclonal light chains from the serum light chains. However, there is a striking degree of homology among the monoclonal light chains regardless of the idiotype character of the parent molecule. Although minor variations are apparent throughout the variable regions, the joining regions are identical among light chains in all of these anti-arsonate antibodies. A particularly notable focus of variation is found at positions 92 and 93 in the third hypervariable region. The possible role of this region in the contribution of the light chain to the arsonate crossreactive idiotype is discussed. These data are consistent with the concept that the anti-arsonate monoclonal light chains originate from the joining of a specific J kappa gene segment to a single germ-line V kappa gene segment. These coding segments are likely further subject to a variety of somatic alterations that generate the modest sequence diversity found among the final protein products.

Amino Acid Sequence↗
PubMed1981

Complete amino acid sequence of variable domains from two monoclonal human anti-gamma globulins of the Wa cross-idiotypic group: suggestion that the J segments are involved in the structural correlate of the idiotype.

The complete amino acid sequences of the variable regions of two human IgM anti-gamma globulins are reported. The two proteins, Sie and Wol, share idiotypic determinants that are distinct from those shared by the two previously sequenced IgM anti-gamma globulins, Lay and Pom [Capra, J. D. & Kehoe, J. M. (1974) Proc. Natl. Acad. Sci. USA 71, 4032-4036; Klapper, D. G. & Capra, J. D. (1976) Ann. Immunol. (Inst. Pasteur) 127C, 261-271.] In contrast to Lay and Pom, Sie and Wol have very little homology in the complementarity-determining hypervariable regions of either their light or heavy polypeptide chains. However, there are only two amino acid differences in the framework portions of the light chains, and the J segments of both chains are homologous. These data suggest that the predominant idiotypic determinant in this cross-idiotypic system may be different than in the Po group and may be either related to their light chain framework structures or to the amino acid sequence in the J segments of these molecules.

Amino Acid Sequence↗
PubMed1981

Identification of H-2-controlled structural variants of the murine Slp protein and demonstration of cis-regulation of its expression.

H-2 haplotype-related structural variation in Slp beta-chains was detected by the limited proteolysis peptide mapping technique. Two distinct peptide patterns were distinguished: Slp.1 was found in strains carrying the S regions of the H-2d and H-2s haplotypes, and Slp.2 was found in strains bearing the S region of H-2w7. These different patterns were expressed codominantly in male (Sd X Sw7)F1 hybrids, whereas only the Slp.2 pattern was expressed in female heterozygotes. The 2 beta-chains are most likely the products of alleles of the Slp structural gene, which must then be located in the murine major histocompatibility complex, very probably in the S region.

Animals↗
PubMed1980

Amino acid sequence of ragweed allergen Ra3.

The complete amino acid sequence of ragweed pollen allergen Ra3 has been determined. The molecule consists of 101 amino acid residues and to date is the only allergen isolated from Ambrosia elatior (short ragweed) which contains carbohydrate. This particular preparation of allergen has a single, unique amino acid sequence, but there is evidence suggesting that, like Ra5, Ra3 isolated from pollen collected in diverse geographical areas shows amino acid sequence variation. The complete amino acid sequence was derived by utilizing only 10--12 mg of material (approximately 1 microM) as a result of recent technical innovations such as DEAE--glass ion exchangers and Polybrene as a useful sequencing aid. This is the second pollen allergen active in man which has been sequenced, and information resulting from these data should be useful in dissecting the molecular mechanisms involved in atopic allergy.

Allergens↗
PubMed1980

T cell hybrids with arsonate specificity. I. Initial characterization of antigen-specific T cell products that bear a cross-reactive idiotype and determinants encoded by the murine major histocompatibility complex.

T cell hybrids have been constructed between the BW5147 thymoma cell line and A/J splenocytes from mice suppressed with the p-azophenylarsonte hapten. Three independently derived cloned lines have been chracterized. Each secretes or sheds a 62,000-dalton antigen-specific product bound by rabbit antisera directed against the arsonate cross-reactive idiotype. In addition, each of the antien-specific molecules contains determinants encoded within the I region of the murine major histocompatibility complex. Peptide mapping analysis indictes that, whereas these molecules are remarkably similar, each is individually distinct in primary structure. The availability of cloned T cell lines that produce antigen-specific idiotype-positive I region-containing products should facilitate a more thorough dissection of the interrelationships of T-B interctions in the arsonate idiotypic system.

Animals↗
PubMed1980

Presence of highly conserved idiotypic determinants in a family of antibodies that constitute an intrastrain cross-reactive idiotype.

It has been shown that A/J anti-p-azophenylarsonate antibodies that share a major cross-reactive idiotype (CRI) comprise a family of closely related, but nonidentical, molecules. Our results demonstrate that 12 of 14 monoclonal hybridoma products that express the CRI have in common at least one highly conserved idiotypic determinant. It is proposed that this reflects conservation of a portion of the amino acid sequence, presumably in hypervariable regions. That the conserved determinant(s0 are located in the region of the hapten-binding site is indicated by the ability of haptens to inhibit idiotype-anti-idiotype interactions involving the conserved, or public determinants.

Animals↗
PubMed1980

Structural studies on induced antibodies with defined idiotypic specificities. IX. Framework differences in the heavy- and light-chain-variable regions of monoclonal anti-p-azophenylarsonate antibodies from A/J mice differing with respect to a cross-reactive idiotype.

Amino terminal amino acid sequence analyses have been performed on the heavy and light chains of induced monoclonal antibodies with specificity for the hapten p-azophenylarsonate. Four of the eight antibodies react with conventional antisera to the previously described A/J anti-arsonate cross-reactive idiotype (CRI). Of the 16 chains analyzed, all but one contain sequence differences in their first framework segment (residues 1-30) that distinguish them from the heavy- and light-chain sequences found in anti-arsonate antibodies isolated from A/J serum or ascites fluid. The presence of such framework differences appears to be independent of whether or not the hybridoma antibodies bear the CRI. In spite of the framework substitutions, all four of the CRI-positive hybridoma antibodies have variable (V)-region frameworks that are very similar to each other and to the CRI-positive molecules found in A/J serum. Two of the four CRI-negative molecules are also structurally similar to the serum antibodies. Two others, however, are strikingly different from any serum anti-arsonate antibody thus far described and appear to reflect a completely separate repertoire of anti-arsonate antibodies in the A/J MOUSE. In addition, serological analyses with an anti-idiotypic antiserum generated against a CRI-positive hybridoma product suggest that each monoclonal antibody may possess individual antigenic specificities different from the determinant(s) detected with the conventional rabbit anti-CRI. The consistent appearance of framework substitutions in what has been thought to be a homogeneous antibody population has important implications for our understanding of the generation of antibody diversity and for the precise chemical definition of an idiotype.

Amino Acid Sequence↗
PubMed1980

Initial characterization of monoclonal antibodies against human monocytes.

Three monoclonal antibodies against human monocytes have been produced by somatic cell fusion. Extensive specificity analysis suggests that these antibodies react with most if not all human peripheral blood monocytes and not with highly purified T or B cells. Initial chemical characterization of the monocyte antigen recognized by two of these antibodies is presented. The molecule is a single polypeptide chain with an apparent molecular weight of 200,000. These reagents should prove useful in the clinical definition of disorders of monocyte differentiation, in studies of monocyte function, and in the elucidation of the genetics and structure of monocyte cell surface antigens.

Animals↗
PubMed1980

Partial amino acid sequences of the murine fourth component of complement (C4): demonstration of homology with human C4 and identification of the amino-terminal subunit in pro-C4.

Radiolabeled murine C4 and C4 precursor (pro-C4) from cultured peritoneal macrophages were purified by immunoprecipitation and preparative gel electrophoresis. The partial NH2-terminal amino acid sequences of the isolated subunits demonstrated that murine C4 alpha, beta-, and gamma-chains all show sequence homology with the corresponding subunits of human C4; of the 10 residues identified in murine C4, all are identical to those in human C4. These data extend to the primary structural level the homology between the murine serum substance (Ss) protein and human C4. Comparisons of the amino acid sequences of murine pro-C4 and the constituent polypeptide chains of secreted C4 indicate that pro-C4 and the C4 beta-chain have an identical amino acid sequence. Both molecules have lysine at position 1, leucine at positions 4, 5, and 6, and phenylalanine at position 7. No sequence homology was found between pro-C4 and either the alpha- or gamma-subunits. These results define the beta-chain as the NH2-terminal subunit in the C4 precursor molecules.

Amino Acid Sequence↗