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Biomedical subjects

D G Klapper

Publications and source records attributed to D G Klapper.

At least 73 records · Page 4Linked to original sources
PubMed1976

Structural studies on protein products of murine chromosome 17: partial amino acid sequence of an H-2Kb molecule.

By use of single internal radiolabels, 17 of the NH2-terminal 27 amino acids of the murine H-2Kb molecule have been assigned. When the amino acid sequence is compared to that of the murine H-2Kk molecule, there is a minimum of six amino acid differences in 19 positions. This high degree of structural diversity confirms, at the level of amino acid sequence, the known polymorphism of the murine H-2 complex. Significant primary str-ctural homology is evident when the murine H-2Kk and H-2Kb sequences are compared to the recently reported partial amino acid sequences of human transplantation antigens. There is modest homology with beta2-mictoglobulin and immunoglobulins, but the available sequence information is insufficient for a satisfactory evaluation of its significance.

Alleles↗
PubMed1976

The partial amino-acid sequence of an H-2K molecule.

Eighteen of the NH2-terminal 27 amino acids of a murine H-2K molecule have been assigned. The approach used was to label murine splenocytes with a single radioactive amino acid, isolate the H-2K molecule by specific immunoprecipitation, electrophorese the dissolved precipitate on sodium dodecyl sulfate polyacrylamide gels, and subject the isolated H-2K peak to amino-acid analysis and automated sequencing.

Amino Acid Sequence↗
PubMed1976

Complete amino acid sequence of the variable domains of two human IgM anti-gamma globulins (Lay/Pom) with shared idiotypic specificities.

On the basis of extensive shared idiotypic specificities, two human IgM anti-gamma-globulins (Lay/Pom) were selected for complete amino acid sequence analysis of their variable domains. Previous studies on the variable regions of the heavy chains of these proteins had shown but eight amino acid differences, only one of which was within a complementarity-determining hypervariable region. The complete amino acid sequence of the variable regions of the light chains of these two proteins is the subject of this report. Protein Lay is a typical VchiI protein with only five 'framework' differences when compared with protein Roy. Protein Pom is best classified as a VchiII, but in the 'framework' there are 16 differences between it and protein Ti. Although there are extensive differences in the first hypervariable region, the second and third light-chain hypervariable regions have an identical sequence. The finding of two identical light-chain and two identical heavy-chain hypervariable regions in these two proteins, which were selected on the basis of their combining specificities and their idiotypic cross-reactions, strongly implicates hypervariable regions in the constitution of the idiotypic determinants and the antibody combining site. Additionally, the finding of identical hypervariable regions in light chains of different V-region subgroups fulfills a prediction of the gene-interaction concept of antibody variability.

Amino Acid Sequence↗
PubMed1976

Structural studies of induced antibodies with defined idiotypic specificities. IV. The heavy chains of anti-streptococcal group A carbohydrate antibodies from Sprague-Dawley rats carrying a cross-reacting idiotype.

The heavy (H) chains of three anti-streptococcal group A carbohydrate antibodies (anti-SACHO) of restricted heterogeneity, elicited in inbred Sprague-Dawley rats, were subjected to 40 cycles of automated Edman degradation. All three antibody H-chain preparations had an identical amino acid sequence and were classified as a variant of the VHIII subgroup of immunoglobulin H chains. A comparison of the H-chain sequence of these antibodies with that of pooled rat gamma chains suggests that a very minor population of H chains (closely related to the VHIII subgroup) has been 'recruited' as a consequence of this immunization. This observation further supports the notion that 'framework' and 'specificity' or 'hypervariable regions' are closely linked.

Amino Acid Sequence↗
PubMed1975

Use of radioimmunoassays to determine the concentration of streptococcal group-specific antibodies in rabbit antisera.

A radioimmunoassay was developed for the quantitation of antibodies to the Group A, A-variant, and C carbohydrates in rabbit streptococcal antisera. The assay employs radiolabeled purified Group carbohydrate which has been tyrosylated to allow for incorporation of 125-I. This assay has an advantage over the intitative precipitin test because it measures non-precipitating antibody in addition to precipitating antibody. Furthermore, 7S anti-IgG in rabbit antisera give a falsely elevated value for the antibody concentration in the quantitative precipitin test. This did not occur with the radioimmunoassay. The assay described is reproducible, sensitive, and uses little antisera.

Adsorption↗
PubMed1973

An idiotypic cross-reaction between allotype a3 and allotype a negative rabbit antibodies to streptococcal carbohydrate.

Two antibodies to Group C streptococcal carbohydrate isolated from an individual rabbit had similar relative binding affinities for a Group C immuno-adsorbent column. Their light chains were similar, if not identical, as were the constant regions of their heavy chains. Differences in the variable regions of the H chains of the two antibodies were detected by chemical analysis. The two antibodies had serologically identical idiotypic determinants although one antibody possessed the a3 allotype and the other had no detectable group a marker. The occurrence of such antibodies indicates the absence of obligatory associations between group a allotypes and idiotypic specificities, despite the fact that both determinants have antigenic components in the V(H) region of the H chain.

Animals↗
PubMedDate not supplied

Production and characterization of a peptide specific, anti-major histocompatibility complex class II, monoclonal antibody.

Monoclonal antibodies to major histocompatibility complex Class II proteins have been useful probes in understanding both the biochemistry and biology of these proteins. Almost all of the monoclonal antibodies previously described have been produced by immunization of mice with living cells. These antibodies react with native Class II proteins, but not usually with denatured material. It has been difficult to obtain specific anti-Class II antibodies which react with denatured proteins. Antibodies reactive with denatured proteins and with well-defined specificities would be useful in studies of Class II assembly and trafficking during the process of antigen presentation. In order to produce such an antibody we have immunized hamsters with a synthetic peptide corresponding to residues 146-177 (beta 1 domain) of the mouse A beta b protein. An antibody has been produced which reacts with the mouse Class II A beta chain from H-2b, H-2d, H-2p, and H-2q mice in immunoblotting assays, but not with the beta chain from H-2f, H-2j, H-2k or H-2s mice. Comparison of the amino acid sequences of these proteins along with the reactivity patterns of the antibody on synthetic peptides corresponding to homologous regions from A beta b, A beta k, A alpha b and Dp suggest that the region of 153 to 155 is critical for the reactivity of this antibody. This antibody does not react with native Class II protein found on the surface of living mouse cells.

Amino Acid Sequence↗