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I van de Rijn

Publications and source records attributed to I van de Rijn.

10 recordsLinked to original sources
PubMed1992

Analysis of the streptococcal hyaluronic acid synthase complex using the photoaffinity probe 5-azido-UDP-glucuronic acid.

The mucopolysaccharide, hyaluronic acid, is an important component of both mammals and pathogenic streptococci. This high molecular weight polymer is synthesized by a membrane-associated, multisubunit hyaluronate synthase which utilizes UDP-glucuronic acid and UDP-N-acetylglucosamine as substrates. Using the photoaffinity probe, [beta-32P]5-azido-UDP-glucuronic acid, three streptococcal membrane proteins (42, 33, and 27 kDa) specifically photoincorporated this probe. Labeling of these proteins was enhanced in the presence of UDP-N-acetylglucosamine, whereas UDP-galactose or UDP-glucose had no effect on incorporation. UDP-glucuronic acid inhibited the labeling of the three proteins in a dose-dependent manner. Detergent-solubilized membrane proteins from transposon-inactivated hyaluronic acid capsule mutants no longer incorporated the probe. This was also the case when membranes from stationary phase organisms were tested. Finally, glucuronic acid no longer was incorporated into high molecular weight hyaluronic acid with either the mutant or stationary phase preparations. Further biochemical analysis will be required to demonstrate the exact role each of the proteins play in hyaluronic acid biosynthesis.

Affinity Labels↗
PubMed1992

Molecular characterization of a locus required for hyaluronic acid capsule production in group A streptococci.

To characterize the production of hyaluronate capsule by the membrane-associated enzyme hyaluronate synthase (HAS), group A streptococci from a recent outbreak of acute rheumatic fever were mutagenized via Tn916 insertion. Acapsular transconjugants harboring multiple, nontandem copies of the transposon were identified and found to lack HAS activity (less than 1% of wild-type levels). Generalized transduction was then performed to determine which Tn916 insertion was responsible for the HAS- phenotype. These marker exchange experiments resulted in the isolation of two distinct classes of acapsular transductants, designated WF61 and WF62. Both transductants also lacked significant HAS activity, and excision of the transposon from WF62 restored capsular hyaluronate production. Southern analysis of WF61 DNA demonstrated a large deletion of genomic DNA adjacent to the Tn916 insertion. This deletion event is presumably responsible for the observed stability of the acapsular phenotype of WF61. Further analyses of transductant whole-cell DNA indicated that the transposon insertions of WF61 and WF62 were separated by 2.5 kb. These studies define a locus required for hyaluronate capsule production in group A streptococci. Further genetic analysis of this locus has identified a gene required for HAS activity which wasd inactivated by TN916 in WF62 and deleted in WF61.

Bacterial Capsules↗
PubMed1992

Characterization of the Streptococcus adjacens group antigen structure.

Serological classification of bacteria requires the presence of an antigen unique to the organism of interest. Streptococci are serologically differentiated by group antigens, many of which are carbohydrates, although some are amphiphiles. This report describes the chemical characterization of the Streptococcus adjacens group antigen structure. Previous studies demonstrated that the amphiphile contained phosphorus, ribitol, galactose, galactosamine, alanine, and fatty acids. Phosphodiester bonds present in the purified group antigen were identified as part of a poly(ribitol phosphate), since ribitol phosphate was the only organic phosphate detected after acid hydrolysis. Hydrofluoric acid cleavage of the phosphodiester bonds generated oligosaccharide repeating units. Gas chromatography-mass spectrometric analysis of the methylated, acetylated oligosaccharide suggested that the repeating unit is a trisaccharide of Galp beta 1-3Galp beta 1-4GalNac with N-acetylgalactosamine attached in beta-linkage to either the number two or the number four carbon of ribitol. The lipid- and carbohydrate-substituted poly(ribitol phosphate) of the S. adjacens group antigen therefore is a unique amphiphile structure, differing in its repeating-unit structure from the polyglycerophosphate structure of the more common gram-positive amphiphile lipoteichoic acid.

Alanine↗
PubMed1979

Characterization and localization of the enzymatic deacylation of lipoteichoic acid in group A streptococci.

Protoplasts of a group A streptococcal strain were shown to contain enzymatic activity capable of converting lipoteichoic acid (LTA) to deacylated lipoteichoic acid (dLTA). The enzyme(s) appear to be located mainly in the membrane, although activity was also found in the cytoplasm. Determination of the sites of cleavage within the LTA molecule was approached by comparing the chemical composition of LTA and native dLTA. Native dLTA, as distinguished from chemically deacylated LTA, was isolated from buffer in which live streptococci had been resuspended and incubated. The chemical data suggest that the enzyme(s) was(were) lipolytic in nature; that is, the conversion of LTA to dLTA was the result of cleavage of the ester linkages between the fatty acids and the remainder of the LTA molecule.

Carboxylic Ester Hydrolases↗
PubMed1979

The occurrence of a protein in the extracellular products of streptococci isolated from patients with acute glomerulonephritis.

The present report compares the extracellular proteins of streptococci by sodium dodecyl sulfate polyacrylamide electrophoresis. A marked variation in the streptococcal extracellualr proteins (SEP) of different strains was detected, even in strains of similar serotypes. It was possible, however, to identify a single protein band that occurred predominantly in the SEP of strains isolated from patients with acute poststreptococcal glomerulonephritis (APSGN). This protein was generally not produced by streptococci obtained from patients without this disease. It appears to be immunologically similar in the various serotypes of streptococci isolated from patients with APSGN and can be demonstrated by immunofluorescence techniques to be present in the glomeruli of these patients.

Antigens, Bacterial↗
PubMed1979

Chemical analysis of changes in membrane composition during growth of Streptococcus pyogenes.

Changes in the structural components of the Streptococcus pyogenes membrane between exponential and early stationary phases of growth are reported. The overall protein composition ranged from 70 to 73% of the dry weight of the membranes, irrespective of the phase of growth from which they were isolated. Amino acid analyses of membranes isolated from streptococci in either the exponential or stationary phase of growth demonstrated that two amino acids, cysteine and tryptophan, were absent. Further analysis of the membrane proteins by sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis demonstrated that there were proteins unique to a particular phase of growth as well as differences in the amount of specific proteins from the various growth phases. In addition, membranes isolated from exponential-phase cultures contained a higher percentage of peripheral protein than did stationary-phase membranes. There also appeared to be an increase in the amount of outer surface proteins during this growth phase. The phosphorus content of the membranes increased during the stationary phase of growth, whereas the sugar composition remained constant. The only sugar found under various conditions of growth in any of the strains was glucose. Total fatty acid content and the mole percent composition of various fatty acids did not change in the different phases of growth. However, the mole percent composition of fatty acids in the membranes of various group A streptococci did differ between strains. Therefore, these results provide evidence that the composition of membranes of S. pyogenes does not remain constant throughout the growth phases of the culture.

Adenosine Triphosphatases↗
PubMed1979

Quantitative immunoelectrophoretic analysis of Streptococcus pyogenes membrane.

The antigenic composition and molecular structure of the plasma membrane of Streptococcus pyogenes (group A; M type 6) were studied by crossed immunoelectrophoresis (XIE) and other related quantitative immunoelectrophoretic techniques. After establishment of a reference pattern of 29 immunoprecipitates, the relative differences in amounts of individual antigens contained in membranes isolated from cells that were harvested during the exponential or stationary phase of growth were examined. Relative increases and decreases in amounts of individual antigens were estimated from the areas subtended by immunoprecipitates after XIE of Triton X-100 extracts. The asymmetric distribution of antigens on the inner and outer surfaces of the membrane was established in absorption experiments with intact, stable protoplasts. Of the 29 immunoprecipitates, 8 appeared to contain antigens exposed on the outer surface of the membrane, whereas 11 appeared to contain antigens either located on the inner surface or unexposed. Six antigens appeared to have limited exposure on the outer surface, and four others remain to be assigned. Certain immunoprecipitates were characterized with respect to enzymatic activity or interaction with the lectin concanavalin A. Reduced nicotinamide adenine dinucleotide dehydrogenase (EC 1.6.99.3), adenosine triphosphatase (EC 3.6.1.3), and polynucleotide phosphorylase (EC 2.3.7.8) were demonstrated by zymogram techniques. The latter two activities were present within the same immunoprecipitate, suggesting the occurrence of a multienzyme complex. In addition, the areas under the immunoprecipitates containing the three enzymatic activities were not affected by absorption of antimembrane immunoglobulin with intact protoplasts and thus appeared to be located on the inner surface of the membrane. The results from absorption experiments also suggested that the exposure of outer protoplast surface antigens was greater on protoplasts from exponential-phase cells than on those from stationary-phase cells, even when found in increased amounts in the latter.

Adenosine Triphosphatases↗
PubMed1977

Group A streptococcal antigens cross-reactive with myocardium. Purification of heart-reactive antibody and isolation and characterization of the streptococcal antigen.

Heart-reactive antibody (HRA) appears in the sera of experimental animals inoculated with group A streptococci as well as patients with acute rheumatic fever. Adsorption of either serum with group A streptococcal membranes will remove the HRA. Blocking experiments between these two types of HRAs have demonstrated that the antibodies are directed towards different antigenic determinants on either the same or different molecules. To isolate and purify the antigen from the group A streptococcus cross-reactive with sarcolemmal sheaths of cardiac myofibers, it became necessary to purify the HRA from rheumatic fever patients' sera. Isolated gamma globulin containing all of the HRA was adsorbed onto human sarcolemmal sheaths. The specific HRA was released by using potassium iodide. Over 99 percent of the purified HRA was shown to bind the sarcolemmal sheath whereas less than 1 percent of the antibody would bind nonspecifically to other material. Preparations of group A streptococcal membrane will bind HRA purified from the sera of acute rheumatic patients at levels of 97 percent or greater. The cross-reactive antigen solubilized by nonionic detergent was purified 120-fold by column chromatography. On sodium dodecyl sulfate polyacrylamide electrophoresis, the antigen was demonstrated to be composed of four polypeptides with mol wt of 32,000, 28,000, 26,000, and 22,000 daltons, respectively. Only proteolytic enzymes could destroy the antigenic determinant whereas glycosidases and lipases had no effect. The purified antigen blocked the binding of purified HRA to normal human heart sections.

Animals↗
PubMed1976

Antibodies reacting with cytoplasm of subthalamic and caudate nuclei neurons in chorea and acute rheumatic fever.

46% of sera from 30 children with rheumatic chorea showed IgG antibody reacting with neuronal cytoplasm of human caudate and subthalamic nuclei. The antibody was also detected in 14% of 50 children with active rheumatic carditis. 55 normal control sera, as well as 148 sera from a broad variety of other disease states showed a low prevalence (1.8-4.0%) of positive reactions. In rheumatic chorea the presence of anti-neuronal antibody appeared to correlate with severity and duration of clinical attacks. Antibody reacting with neuronal cytoplasm was completely removed by absorption with Group A streptococcal membranes or with isolated human neurons from caudate nucleus. Partial absorption of antibody was also recorded using Group A cell wall preparations but not with Group A carbohydrate. No absorption of positive reactions was seen with streptococcal Group D membranes or cell walls. In rheumatic chorea, anti-neuronal antibody appeared to represent cross-reaction with antigens shared by Group A streptococcal membranes.

Acute Disease↗