Localization of enzymes in the microbial cell

Isolation and Characterization of a Protective Antigen-Containing Particle from Culture Supernatant Fluids of Erysipelothrix rhusiopathiae

The mouse-protective activity of Erysipelothrix rhusiopathiae culture supernatant fluids exists in a polydisperse form, ranging in density from aggregates which sediment at 10,000 x g for 3 hr to soluble units which will not sediment at 198,000 x g for 12 hr. A partially purified protective antigen has been isolated from the aggregates sedimented from a concentrate of the culture supernatant fluid at 20,000 x g for 3 hr. These aggregates contained the major protective antigen or antigens of E. rhusiopathiae, since, in addition to inducing active immunity, they adsorbed essentially all of the passively protecting antibody from rabbit antiserum produced by immunization with whole culture. The protective activity in these aggregates was destroyed by trypsin and greatly diminished by muramidase and heating at 64 C, but was not affected by lipase or ribonuclease.

Solubilization and Characterization of a Protective Antigen of Erysipelothrix rhusiopathiae

A particulate fraction of Erysipelothrix rhusiopathiae cultures has been subjected to butanol extraction and treatment with surface-active agents in an attempt to solubilize a protective antigen. The particulate fraction was partitioned into the butanol layer but was not solubilized. Only sodium dodecyl sulfate solubilized the particles. The soluble protective activity was not sedimented by centrifugation at 198,000 x g for 12 hr but was excluded by Sephadex G-200. Immunodiffusion studies of the soluble fraction demonstrated eight antigens, five of horse serum origin and three of E. rhusiopathiae origin. Ultracentrifugation indicated that spontaneous reaggregation occurred after removal of the sodium dodecyl sulfate. Analytical ultracentrifugation showed that 90% of the sodium dodecyl sulfatetreated material migrated as a single homogeneous 3.5S component. The physical and biological characteristics of the protective activity suggest that the protective antigen is a glyco-lipoprotein.

Identification of a toxic cellular component of group A streptococci as a complex of group-specific C polysaccharide and a protein

The toxic cellular component of Group A streptococci, which produces a chronic multinodular lesion of the dermal connective tissue of rabbits, has been isolated by means of differential centrifugation and electrophoresis. The substance appeared to be a macromolecular complex of polysaccharide and protein, the polysaccharide having the serological and chemical characteristics of the group-specific C substance. Evidence is presented indicating that the polysaccharide moiety is an essential part of the toxic complex. It is suggested that further studies of this material may help elucidate the mechanism of tissue damage in the non-suppurative sequelae of Group A streptococcal infections.

Principles of macromolecular organization and cell function in bacteria and archaea

Structural organization of the cytoplasm by compartmentation is a well established fact for the eukaryotic cell. In prokaryotes, compartmentation is less obvious. Most prokaryotes do not need intracytoplasmic membranes to maintain their vital functions. This review, especially dealing with prokaryotes, will point out that compartmentation in prokaryotes is present, but not only achieved by membranes. Besides membranes, the nucleoid, multienzyme complexes and metabolons, storage granules, and cytoskeletal elements are involved in compartmentation. In this respect, the organization of the cytoplasm of prokaryotes is similar to that in the eukaryotic cell. Compartmentation influences properties of water in cells.

Oxido-reductive functions of Entamoeba histolytica in relation to virulence

Entamoeba histolytica can reduce nitro-blue tetrazolium (NBT) in Hank's balanced salt solution to almost the same extent as in Eagle's minimal medium. Further, this reduction was stimulated only to a minor degree by glucose, pyruvate and DL-serine, substrates known to support respiratory activity (O2 uptake) in E. histolytica. However, both NADH and NADPH increased NBT reduction several-fold, the effect being greater with NADPH. A sizeable proportion of this endogenous dye-reducing capability (in Hank's solution) was associated with low-speed sediments obtainable from amoebic homogenates, which also shared the bulk of 125I labelling (when the homogenates were prepared after surface labelling with Na 125I). Conversion of the dye to formazan was strongly inhibited by -SH blocking agents, but was not influenced by rotenone and antimycin A. The activity was also inhibited by H2O2, but stimulated by catalase. Superoxide dismutase only slightly curtailed NBT reduction in intact cells, but inhibited it in homogenates in a concentration-dependent manner to a maximal extent of 33%. Almost the same degree of curtailment of this activity was induced by anaerobic conditions. Both concanavalin A (Con A) and phorbol myristate acetate stimulated the activity in intact cells, though the effect of Con A was nullified by alpha-methyl mannoside. Both NBT-reducing capability and alcohol dehydrogenase activities were higher in the more virulent IP:106 strain, and they increased with time in cultures of NIH:200 in a cholesterol-enriched environment.

KINASES OF STREPTOCOCCUS FAECALIS I

Moore, L. Daneo (University of Pennsylvania, Philadelphia) and D. J. O'Kane . Kinases of Streptococcus faecalis . I. Enzyme localization. J. Bacteriol. 86: 766–772. 1963.—Cell-free extracts of Streptococcus faecalis 10C1 were found to contain a membrane-associated, particulate hexokinase with activity toward glucose, fructose, mannose, and, to a lesser extent, galactose, gluconate, and mannitol. In addition, the cell cytoplasm contained kinases specific for fructose, mannose, and galactose. No specific kinases were found for gluconate or mannitol, although in the presence of mannitol adenosine triphosphate was utilized by a cytoplasmic fraction. The possibility is discussed that the main pathways of gluconate and mannitol metabolism are oxidation followed by phosphorylation.

Location of enzymes in Azotobacteragilis

Robrish, Stanley A. (University of California, Davis) and Allen G. Marr. Location of enzymes in Azotobacter agilis. J. Bacteriol. 83: 158-168. 1962.-If the cells of Azotobacter agilis are disrupted by osmotic shock, respiratory enzymes and the compounds characteristic of cell wall and cytoplasmic membrane are recovered almost completely in large particles. The large particles obtained by osmotic shock were found by electron microscopy to consist of cell wall, cell membrane, and an internal membrane appearing as either vesicles or tubules in section. These envelopes are free of all the soluble cytoplasmic material and are essentially free of ribosomes. Small particles obtained by osmotic shock are ribosomes; small particles obtained by sonic oscillation consist of both ribosomes and amorphous material, presumably fragments of the envelope.

SUBMICROSCOPIC PARTICLES IN EXTRACTS OF AZOTOBACTER AGILIS1

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Sonic disruption of Azotobacter vinelandil

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