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M McCARTY

Publications and source records attributed to M McCARTY.

18 recordsLinked to original sources
PubMed1962

Variation in the group-specific carbohydrate of group C hemolytic Streptococci.

Certain strains of Group C hemolytic streptococci, termed Group C-intermediate, contain a group-specific carbohydrate antigen which gives a precipitin cross-reaction with A-variant antiserum. The carbohydrate antigens of these strains have a rhamnose:hexosamine ratio ranging from 2.4 to 2.6 whereas the ratio of typical Group C strains varies between 1.1 and 1.7. N-acetylgalactosamine, the major hexosamine in all of these strains is the principle determinant of Group C specificity. The high concentration of rhamnose in the C-intermediate carbohydrate suggests that a portion of the rhamnose oligosaccharide side chains are devoid of terminal N-acetylgalactosamine and thus react with Group A-variant antiserum. This view is supported by the fact that the induced variant enzyme, which destroys A-variant carbohydrate reactivity with the liberation of rhamnose oligosaccharides, has a similar action upon the Group C-intermediate carbohydrate. C-intermediate carbohydrate, after treatment with variant enzyme which removed approximately 25 per cent of the rhamnose, does not react with A-variant antisera.

Carbohydrate Metabolism↗
PubMed1962

Studies on the chemical structure of the streptococcal cell wall. II. The composition of group C cell walls and chemical basis for serologic specificity of the carbohydrate moiety.

The trypsinized cell walls of Group C streptococci contain two components, the group-specific carbohydrate and a mucopeptide polymer. Hot formamide extraction of Group C cell walls results in a soluble group-specific carbohydrate fraction and an insoluble mucopeptide residue. This mucopeptide, similar in composition to that of Groups A and A-variant streptococci, contains N-acetylglucosamine, N-acetylmuramic acid, alanine, glutamic acid, lysine, and glycine. It is dissolved by the muralytic enzymes, including lysozyme, which does not attack the whole cell wall. Lysis of the cell wall by phage-associated lysin results in the release of soluble fragments composed of the elements of mucopeptide. Group C carbohydrate extracted with formamide is composed primarily of N-acetylgalactosamine and rhamnose. Serological studies suggest that the specificity of Group C carbohydrate is determined by the N-acetylgalactosamine.

Carbohydrates↗
PubMed1959

Studies of L forms and protoplasts of group A streptococci. I. Isolation, growth, and bacteriologic characteristics.

L forms of Group A streptococci have been isolated by the use of penicillin gradient agar plates. Osmotically fragile protoplasts of Group A streptococci have been obtained by the use of Group C phage-associated lysin which lyses Group A streptococci and their isolated cell walls. Membranes surrounding these enzymatically derived protoplasts have been isolated, and chemical and immunological studies indicate that they are free of cell wall carbohydrate and M protein. The streptococcal protoplasts reproduce as colonies which are morphologically indistinguishable from streptococcal L forms. Evidence is presented to show that these two streptococcal derivatives are serologically and physiologically related to each other as well as to the parent streptococcal strain from which they were isolated.

Bacteriophages↗
PubMed1959

The occurrence of polyglycerophosphate as an antigenic component of various gram-positive bacterial species.

A bacterial substance has been described which gives a precipitin reaction with certain antisera to Group A streptococci. The precipitating antigen is present in various Gram-positive bacteria, including most hemolytic streptococci, staphylococci, and aerobic sporulating bacilli. It is not present in any of the Gram-negative species examined or in pneumococci, clostridia, or corynebacteria. Analysis of purified preparations obtained from Group A streptococci indicates that the antigen is a simple polymer of glycerophosphate. The identification has been confirmed by immunochemical studies, including precipitin tests and specific inhibition with synthetic polyglycerophosphates. In addition, the infrared spectra of bacterial and synthetic polyglycerophosphate are shown to be closely similar. Immunochemical analysis suggests that the amount of polyglycerophosphate present in Group A streptococci and staphylococci is approximately 1 per cent of the dry weight of the cells. The cellular localization and function of the polyglycerophosphate have not been established.

Antigens↗
PubMed1958

Further studies on the chemical basis for serological specificity of Group A streptococcal carbohydrate.

Azoproteins prepared with p-aminophenyl-beta-N-acetyl-glucosaminide react in precipitin tests with Group A streptococcal antisera. The reaction is nonreciprocal, and antisera to the azoprotein do not react with Group A carbohydrate. Phenyl-N-acetyl-glucosaminides inhibit the reaction of Group A carbohydrate with homologous antisera and with antisera to the azoprotein. The beta-anomer is more effective as an inhibitor than the alpha-anomer. Formation by a soil bacillus of the enzyme which removes N-acetyl-glucosamine from Group A carbohydrate is induced by phenyl-beta-N-acetyl-glucosaminide but not by the alpha-compound. The enzyme, like the glucosaminidase of emulsin, appears to be specific for beta-glucosaminides. Neither the induced enzyme nor emulsin effectively remove all of the N-acetyl-glucosamine from the azoprotein antigens. The findings support the view that beta-N-acetyl-glucosaminide side chains represent the major antigenic determinant of Group A streptococcal carbohydrate.

Antigens↗
PubMed1955

Variation in the group-specific carbohydrate of group A streptococci. I. Immunochemical studies on the carbohydrates of variant strains.

The phenomenon of apparent loss of group-specific carbohydrate in the course of mouse passage of group A streptococci has been subjected to further study, and several additional variants showing this property have been described. The loss of group reactivity is shown to be due to an alteration in the chemical structure and serological specificity of the cell wall carbohydrate. This alteration appears to be essentially the same in each of the variants available for study. The carbohydrate of the variant strains (V) contains the same two monosaccharide components as the group A carbohydrate (A), but they are present in different proportions. Precipitating sera reactive with V carbohydrate have been prepared, and the A and V carbohydrates have been compared by qualitative and quantitative precipitin analysis. A second type of variation has been encountered during mouse passage. This variation is characterized by the occurrence of a cell wall carbohydrate (I) intermediate in chemical and serological properties between the A and V carbohydrates. The I carbohydrate reacts with both A and V antisera and does not appear to be a simple mixture of A and V carbohydrate. Similarly, antisera against the intermediate strain contain antibodies reactive with both A and V carbohydrates, and evidence is presented indicating that in part this represents antibody with double specificity.

Animals↗
PubMed1954

The occurrence during acute infections of a protein not normally present in the blood. V. Physical-chemical properties of the C-reactive protein crystallized by a modified technique.

A method is described for obtaining crystalline C-reactive protein from serous fluids in which the protein is associated with lipid. Most pathological fluids currently available as a source of this protein appear to fall in this category. Crystalline C-reactive protein has its isoelectric point at pH 4.82 as determined by free electrophoresis in McIlvaine's buffer. Its mobility in the electrophoresis cell, both alone and after addition to normal serum, coincides with that of the beta-globulin fraction of the serum. In contrast to this finding, by the method of zone electrophoresis on a starch supporting medium the protein migrates with the gamma(1)-globulin. The significance of this discrepancy is discussed. Studies in the ultracentrifuge indicate an s(20,w) of 7.5.

Blood Proteins↗
PubMed1951

The occurrence in the rabbit of an acute phase protein analogous to human C reactive protein.

The occurrence in the rabbit of an acute phase protein analogous to human C-reactive protein has been confirmed. The acute phase protein of the rabbit reacts with a special form of the pneumococcal somatic polysaccharide, designated Cx polysaccharide, in the same manner that the human C-reactive protein reacts with the classical C polysaccharide. The method of preparation and some of the properties of the Cx polysaccharide are described. The rabbit Cx-reactive protein has been shown to be remarkably similar to human C-reactive protein in its general properties and in the conditions which govern its appearance in the blood. It has been obtained in crystalline form, and appears to be antigenically distinct from the proteins of normal rabbit serum.

Acute-Phase Proteins↗
PubMed1949

The inhibition of streptococcal desoxyribonuclease by rabbit and human antisera.

Rabbit antisera against partially purified streptococcal desoxyribonuclease inhibit the action of the enzyme on its substrate. The activity of pancreatic desoxyribonuclease is not affected by these antisera. Similarly antibody against pancreatic nuclease does not inhibit the streptococcal enzyme. Certain patients develop inhibitory antibody to streptococcal desoxyribonuclease following streptococcal infections, occasionally in very high titer, although the proportion of patients showing an antibody response appears to be lower than in the case of streptokinase and streptolysin O. The pattern of antibody response to desoxyribonuclease has been compared to that of streptokinase and streptolysin O in a group of ninety patients from an epidemic of scarlet fever.

Animals↗