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Biomedical subjects

R M Krause

Publications and source records attributed to R M Krause.

At least 73 records · Page 4Linked to original sources
PubMed1970

The emergence of antibodies with either identical or unrelated individual antigenic specificity during repeated immunizations with streptococcal vaccines.

Electrophoretically monodisperse antibody components in rabbit antisera to the carbohydrates of the Groups A and C streptococci have been examined for their individual antigenic specificity. In these antibody components which were isolated by preparative electrophoresis, individual antigenic specificity was confined to the specific antibody and was absent in the nonantibody gamma-globulin. Radioprecipitation experiments and the use of immune absorbent columns constructed from goat anti-antisera, which had been absorbed with fraction II, revealed that all the specific antibody in an electrophoretically monodisperse component was reactive with the homologous anti-antibody. Antibodies with either identical or distinct individual antigenic specificities may occur in the same rabbit with repeated immunizations. Antibodies with identical antigenic specificity had identical electrophoretic mobility, whereas antibodies with unrelated antigenic specificities had distinct electrophoretic mobilities. In the interval between immunizations, if antibody to the carbohydrate antigen was absent, there was no detectable antibody with individual antigenic specificity.

Animals↗
PubMed1970

Induction of rabbit antibody with molecular uniformity after immunization with group C streptococci.

Antibodies with uniform properties may occur in rabbits after immunization with Group C streptococci. These precipitating antibodies possess specificity for the group-specific carbohydrate. Not uncommonly, their concentration is between 20 and 40 mg/ml of antiserum. Evidence for molecular uniformity in the case of one of these antibodies, described in detail here, includes: individual antigenic specificity; monodisperse distribution of the light chains by alkaline urea polyacrylamide disc electrophoresis; and a single amino acid in each of the first three N-terminal positions of the light chains. When the amino acid sequence of rabbit antibody b+ light chains (kappa type) are aligned against their human kappa counterparts, a definite homology is observed between the N-terminus of the human and the rabbit variable region.

Amino Acid Sequence↗
PubMed1970

Allotype exclusion in uniform rabbit antibody to streptococcal carbohydrate.

Rabbit antibodies to streptococcal polysaccharide are described which show selectivity of expression of the allotypic specificities on both the heavy (H) and light (L) chains. One of these antibodies binds weakly to Sephadex. A purification method based on this binding has yielded antibody completely lacking any group a allotypic marker on its H chains.

Animals↗
PubMed1969

Rabbit antibodies to streptococcal carbohydrates. Influence of primary and secondary immunization and of possible genetic factors on the antibody response.

In a search for possible genetic factors which may influence the immune response to the streptococcal carbohydrates, over 100 rabbits have been immunized with streptococcal vaccines, and representative examples of high and low response pairs mated. The concentration of precipitins to the group-specific carbohydrates has been measured in the antisera following primary intravenous immunization with heat-killed streptococcal vaccines, Group A, Group A-variant, and Group C. For the majority of rabbits, the concentration of precipitins varied between 1 and 10 mg/ml of antiserum; while in the minority, it was between 11 and 32 mg/ml. The offspring of rabbits with high antibody levels had a significantly higher concentration of antibody than was seen in the offspring of rabbits of low response parents. Such data suggest that the magnitude of the immune response to these carbohydrate antigens is under some form of genetic control. Not uncommonly in rabbits with hyper-gamma-globulinemia following primary immunization, the group-specific precipitins are the predominant component of the gamma-globulin. An unusual feature of such components is that they are electrophoretically monodisperse, and possess individual antigenic specificity. In this respect they resemble the myeloma proteins. When a response of this sort is not seen after primary immunization, it may occur after secondary immunization. Therefore, prior exposure to the same or closely related antigen may also have an influence on the occurrence of high concentrations of such uniform antibodies.

Animals↗
PubMed1969

Amino acid sequence restriction in rabbit antibody light chains.

Light chains were obtained from IgG rabbit antibodies to the group-specific carbohydrates of groups A and C streptococci. An analysis of the amino acid alternatives which exist at the first three positions of the N-terminus in both light-chain preparations shows a marked restriction in amino acid sequence heterogeneity when compared with preimmune light chains. Both of these related, but immunologically distinct, antigenic determinants select the same uncommon subpopulation of rabbit light chains.

Amino Acid Sequence↗
PubMed1969

Chemical studies on the structure of mucopeptide isolated from Streptococcus bovis.

Mucopeptides isolated from Streptococcus bovis cell walls were found to be composed of alanine, glutamic acid, lysine, and threonine in a mole ratio of 3:1:1:1. A dipeptide, N(epsilon)-lysylthreonine, was isolated from S. bovis mucopeptide by ion-exchange chromatography. This finding suggests that threonine is associated with the bridge which cross-links adjacent tetrapeptides by connecting the epsilon-amino group of lysine of one tetrapeptide to the carboxyl group of d-alanine of another to form the mucopeptide matrix.

Alanine↗
PubMed1968

The individual antigenic specificity of antibodies to streptococcal carbohydrates.

Although a single electrophoretically uniform antibody component with specificity for the group carbohydrate may comprise the bulk of the gamma-globulin in rabbits immunized with streptococcal vaccines, this is not always the case. Not infrequently, electrophoresis may reveal multiple antibody components. Nevertheless, it has been feasible by various preparative procedures to isolate from a single antiserum at least two antibody components with similar reactivity for the carbohydrate both of which are electrophoretically monodisperse. Light chains from such antibodies reveal a restricted pattern when examined by disc electrophoresis. Antibodies to streptococcal carbohydrates have been examined for their individual antigenic specificity. Goats were immunized with isolated Group C and Group A-variant antibodies raised in rabbits. Individual antigenic specificity of these antibodies was brought out by absorption of the goat anti-antiserum with Fr II of pooled normal rabbit sera. Additional absorption of the goat anti-antisera with Fr II diminished but did not eliminate the reactivity for the homologous antibody. Immunoelectrophoretic studies with papain fragments of purified streptococcal antibodies localized the specificity to the Fab fragment. Specificity was not confined to the isolated light chains of the antibody.

Animals↗
PubMed1968

Immunochemical studies on the cross-reactivity between streptococcal and staphylococcal mucopeptide.

Particulate mucopeptides of Group A-variant streptococci and Staphylococcus aureus, solubilized by ultrasonic treatment, give a precipitin reaction with the sera of rabbits immunized with Group A-variant streptococci. gamma-G globulin antibodies have been recovered from these sera which react with the mucopeptides but not with the Group A-variant carbohydrate. The immunochemical basis for the cross-reactivity between the streptococcal and staphylococcal mucopeptides was investigated in detail. Three chemically different fractions have been isolated from enzymatic digests of staphylococcal mucopeptide and were employed as haptenic inhibitors of the precipitin reaction. A fraction consisting of the peptide moiety of mucopeptide was the strongest inhibitor, whereas the hexosamine-rich fraction was less effective. The third fraction, rich in glycine, was least effective. It is suggested that the immunologic cross-reactivity between streptococcal and staphylococcal mucopeptide is due to the fact that these two substances contain chemically similar tetrapeptides. The hexosamine polymer which is identical for both mucopeptides may also contribute to their cross-reactivity.

Amino Acids↗
PubMed1967

Immunochemical studies on the group and type antigens of group F streptococci and the identification of a grouplike carbohydrate in a type II strain with an undesignated group antigen.

Two antigens, the group-specific carbohydrate and the Type II carbohydrate, have been isolated by cellulose column chromatography from a formamide extract of a Group F streptococcus. Chemical and immunologic analyses indicate that both antigens are free of other cellular components. Both antigens are components of the cell wall although the Type II antigen is probably more superficial than the group antigen. The Type II antigen is composed of rhamnose, glucose, galactose, and galactosamine. The Group F antigen is composed of rhamnose, glucose, galactosamine and a small percentage of glucosamine. A grouplike carbohydrate and the Type II carbohydrate have been isolated from a streptotoccal strain which lacks a serologically detectable streptococcal group antigen. This grouplike carbohydrate, which does not cross-react immunologically with Group F serum, is composed of rhamnose, galactose, and glucosamine. No chemical or immunological differences were observed between the Type II antigen isolated from the Group F strain and the Type II antigen isolated from the nongroupable strain.

Animals↗
PubMed1967

Cell walls of group D streptococci. II. Chemical studies on the type 1 antigen purified from the autolytic digest of cell walls.

Autolysis of group D, type I cell walls by an indigenous autolytic enzyme results in the solubilization of the type I antigen. The antigen was purified from the autolytic digest by diethylaminoethyl cellulose chromatography. Chemical analysis of the purified type 1 antigen revealed glucose, glucosamine, galactosamine, rhamnose, ribitol, phosphorus, and residual peptoglycan components. This analysis suggested that the type I antigen is a heteropolymer which may contain a ribitol teichoic acid. The antigen purified by the procedure outlined here is higher in phosphorus content, lower in peptidoglycan, and more reactive serologically than the antigen prepared by methods previously described.

Alanine↗