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Biomedical subjects

R R Russell

Publications and source records attributed to R R Russell.

At least 127 records · Page 7Linked to original sources
PubMed1979

Glucan-binding proteins of Streptococcus mutans serotype c.

Three glucan-binding proteins have been isolated from the extracellular fluid cultures of Streptococcus mutans serotype c. These proteins were adsorbed to glucans containing 1,3-alpha or 1,6-alpha bonds and linked to various chromatographic supports: they were eluted from columns by a dextran solution. Glucosyltransferase activity was associated with two of the glucan-binding proteins.

Bacterial Proteins↗
PubMed1979

Wall-associated protein antigens of Streptococcus mutans.

When heat-killed whole organisms of Streptococcus mutans strain Ingbritt (serotype c) were injected into rabbits, antibodies to at least 12 antigens were detectable by crossed immunoelectrophoresis. In contrast, when rabbits were immunized with organisms which had been subjected to extraction with the detergent sodium dodecyl sulphate (SDS), antibodies to only two protein antigens were found. These two proteins (A and B), while existing in a form apparently closely associated with peptidoglycan, could also be recovered from homogenates of whole organisms after sonication and from culture filtrates. Antigenic material was excreted throughout growth. SDS-polyacrylamide gradient gel electrophoresis showed A to have a molecular weight of 29 000, while B had a molecular weight of 190 000. Antigen B was purified to apparent homogeneity as judged by SDS-polyacrylamide gel electrophoresis and isoelectric focusing. All of six strains of serotype c examined produced antigen B. Strains of serotypes e and f also produce antigenically identical proteins and strains of serotypes d and g produce proteins which cross-reacted with antigen B. Antigen B was specifically precipitated by rabbit antiserum to human heart tissue.

Antibody Formation↗
PubMed1978

Immunological relationships of some non-pathogenic Neisseria.

A collection of nine stock strains of non-pathogenic Neisseria species and one strain of Branhamella catarrhalis has been examined serologically by a simple immunodiffusion technique utilising cultures growing on solid medium.

Antibodies, Bacterial↗
PubMed1978

Glycosyltransferases of Streptococcus mutans strain Ingbritt.

The glycosyltransferases of S. mutans strain Ingbritt have been resolved by SDS-polyacrylamide gel electrophoresis, followed by incubation in the presence of non-ionic detergent to restore enzyme activity. A group of high molecular weight proteins synthesizing glucans has been identified, as well as three distinct fructan-synthesizing activities. The glucan-forming enzymes have been purified by affinity chromatography on insoluble glucan, followed by gel chromatography in SDS, and antiserum to the purified enzymes has shown that they are antigenically identical within serotypes c, e and f, and cross-react strongly with serotype b.

Antigens, Bacterial↗
PubMed1976

Two-dimensional SDS-polyacrylamide gel electrophoresis of heat-modifiable outer-membrane proteins.

An examination has been made of the effect which temperature of solubilization has upon the subsequent migration in SDS-polyacrylamide gel electrophoresis of proteins from the cell envelopes of Escherichia coli K12 and Neisseria sicca ATCC 9913. Conventional electrophoresis in tubes revealed substantial differences in the staining patterns of gels, depending upon whether the envelope samples were solubilized at 37 degrees C or 100 degrees C; in the case of N. sicca at least 6 of 13 discernible bands displayed heat-modifiable behavior. The relationship of the bands produced by each of the two temperatures was investigated by a two-dimensional electrophoresis procedure, in which a sample was solubilized at 37 degrees C and run in a usual cylindrical gel; the entire gel was then resolubilized at 100 degrees C, and laid along an acrylamide slab for electrophoresis in the second dimension. It was found that "free endotoxin" of both organisms examined contained the same major proteins as the total envelope fraction, and that these free endotoxin proteins showed the same heat-modifiable properties as when present in total envelopes.

Bacterial Proteins↗
PubMed1976

Comparison of the cell envelope proteins of Micrococcus cryophilus with those of Neisseria dnd Branhamella species.

In an attempt to elucidate the relation between Micrococcus cryophilus, Neisseria caviae, Neisseria ovis, and Branhamella catarrhalis, fractions derived from outer membranes of a strain of each organism were examined for protein composition by SDS - polyacrylamide gel electrophoresis. Micrococcus cryophilus outer membrane protein showed extensive similarities to that of N. ovis and contained a heat-modifiable protein which behaved almost identically with the corresponding bands previously shown to exist in N. caviae and N. ovis. Branhamella catarrhalis protein was distinctly different from those of M. cryophilus and the two 'false neisserias' N. caviae and N. ovis.

Bacterial Proteins↗
PubMed1975

Envelope proteins in Neisseria.

The proteins of the cell envelope of Neisseria sicca strain ATCC 9913 have been examined by SDS - polyacrylamide gel electrophoresis. Some 20 proteins were resolved from the total envelope fraction, and nearly all of these were found to be localized in the outer membrane. Preparations of the "free-endotoxin" fraction differ from the outer membrane only in lacking a few minor proteins. The behavior of several of the envelope proteins on electrophoresis can be modified by changing the temperature of sample solubilization, and also by alteration of the growth medium. Experiments with phosphate-limited cultures showed that certain periplasmic proteins are closely associated with free endotoxin. Mutations which result in altered outer membrane permeability to antibiotics were found to cause changes in cell envelope protein composition. A comparison of the envelope proteins of eight species of non-pathogenic Neisseria showed that each had a characteristic composition. A classification of the organisms based on the relatedness of the protein patterns seen on SDS-polyacrylamide gels was in close agreement with classifications based on more usual methods.

Anti-Bacterial Agents↗
PubMed1975

SDS-polyacrylamide gel electrophoresis of lipopolysaccharides.

Lipopolysaccharides (LPS) prepared from four different species of Neisseria have been separated by SDS-polyacrylamide gel electrophoresis. Each LPS possessed a characteristic mobility on gels. Examination of the effect of acrylamide concentration on migration illustrated that the basis of the separation was molecular size and not intrinsic charge.

Electrophoresis, Polyacrylamide Gel↗
PubMed1974

Effect of the inhibition of protein synthesis on the Escherichia coli cell envelope.

The consequences for cell envelope integrity of Escherichia coli K-12 of the inhibition of protein synthesis by a variety of means have been examined. Protein synthesis was blocked by the antibiotics chloramphenicol and streptomycin, by amino acid starvation of an amino acid auxotroph, and by inactivation of temperature-sensitive aminoacyl transfer ribonucleic acid synthetase and ribosomal mutations. Closely similar morphological and physiological effects were found irrespective of the means by which protein synthesis was blocked. Scanning electron microscopy revealed a spectrum of changes after protein inhibition, with granular material derived from cells and spheroplasts commonly seen. Streptomycin caused additional changes manifested in a collapsed appearance of treated cells. Measurements of the release of lipopolysaccharide from the cell surface, alterations in outer membrane penetrability, and lysis of lysozyme-ethylenediaminetetraacetic acid-treated cultures also showed that the various inhibitory treatments all had similar effects on cell envelope properties. The close correspondence between the effects seen with antibiotic-treated cultures and those in which protein synthesis inhibition was achieved by use of mutants indicates that the effects of chloramphenicol and streptomycin on the cell envelope are indirect consequences of ribosomal block, rather than due to multiple sites of action of the antibiotics.

Bacterial Outer Membrane Proteins↗
PubMed1972

Temperature-sensitive osmotic remedial mutants of Escherichia coli.

A collection of temperature-sensitive mutants of Escherichia coli K-12 was examined for ability to grow at the restrictive temperature when the osmotic pressure of the medium was increased. Five of the fourteen mutants were found to be osmotic remedial. Four strains containing temperature-sensitive, osmotic-remedial mutations affecting aminoacyl-transfer ribonucleic acid synthetases were found to have altered permeability characteristics which may be attributable to changes in the lipopolysaccharide layer of the cell envelope at restrictive temperatures.

Amino Acyl-tRNA Synthetases↗
PubMed1971

New suppresor in Escherichia coli.

During the genetic mapping of a mutation in the pheS gene which confers temperature sensitivity on a strain of Escherichia coli K-12, an extragenic suppressor was discovered which restores ability to grow at the restrictive temperature. The suppressor, which has been named supQ, is cotransduced by bacteriophage P1 with the purE marker. SupQ does not suppress a number of amber or ochre mutations. SupQ(-) is carried by the prototrophic Hfr Hayes strain AB259, and the presence of the supQ(-) allele impairs the growth of this strain at 42 C.

Chromosome Mapping↗
PubMed1971

Mutants of Escherichia coli unable to make protein at 42 C.

Members of a collection of mutants of Escherichia coli unable to form colonies on nutrient agar at 42 C have been characterized on the basis of their growth response to a shift from 32 to 42 C in liquid medium. Forty-four mutants, which show an abrupt, nonlethal cessation of growth when moved to the restrictive temperature, have been characterized with respect to the effect of the mutation responsible for temperature sensitivity on deoxyribonucleic acid, ribonucleic acid, and protein synthesis. In 12 mutants, the mutation causing temperature sensitivity of growth primarily affects protein synthesis, in each case through an altered aminoacyl-transfer ribonucleic acid synthetase. Mutants with temperature-sensitive glutamyl-, phenylalanyl-, and valyl-transfer ribonucleic acid synthetases have been obtained, and the genes specifying these enzymes have been mapped by conjugation and transduction. Another mutant has been shown to possess a temperature-sensitive tryptophanyl-transfer ribonucleic acid synthetase, but this is not responsible for inability to grow at 42 C on media containing tryptophan.

Agar↗