Streptococci proteins

Anistreplase (streptokinase- plasminogen complex) streptococci protein streptococci plaminogen, which is then cleaved to form plasmin. Plasmin mediate fibrinolysis. Systemic lytic state and immunogenicity may limit its use. Because antistreplase is aheadly lined to plaminogen, the onset of fibrinolytic is faster. These enzymes are not fibrin-specific. 

Devulapalle KS, Goodman SD, Gao Q, Hemsley A, Mooser G (1997) Knowledge-based model of a glucosyltransferase from the oral bacterial group of mutans streptococci. Protein Sci 6 2489-2493... 

Streptokinase. Streptokinase is a single-chain protein containing 415 amino acids, mol wt of 45,000 to 50,000 (261,284—286). It is produced by P-hemolytic streptococci and is not an enzyme per se. Only after streptokinase combines with plasminogen on a 1 1 basis to form a... 

Streptokinase. The fibrinolytic activity of streptokinase, isolated from strains of hemolytic Streptococci, was first demonstrated in 1933 (63). Streptokinase is a secreted protein product inasmuch as filtrates free of demonstrable bacteria were found to dissolve fibrin clots with rapidity. 

Resistance to phagocytosis is sometimes associated with specific components of the cell wall and/or with the presence of capsules surrounding the cell wall. Classic examples of these are the M-proteins of the streptococci and the polysaccharide capsules of pneumococci. The acidic polysaccharide K-antigens of Escherichia coli and Sal typhi behave similarly, in that (i) they can mediate attachment to the intestinal epithelial cells, and (ii) they render phagocytosis more difficult. Generally, possession of an extracellular capsule will reduce the likelihood of phagocytosis. 

J.J. Langone, Protein A of Staphylococcus aureus and related immunoglobulin receptors produced by streptococci and pneumonococci. Adv. Immunol. 32,157—252 (1982). 

Likewise, for zinc, bacteria have developed active uptake systems (Hantke, 2001). In many bacteria the high-affinity Zn2+ uptake system uses an ABC transporter of the cluster 9 family, which mostly transports zinc and manganese and is found in nearly all bacterial species. First identified in cyanobacteria and pathogenic streptococci, but also found in E. coli, the system is encoded by three genes ZnuABC and consists of an outer membrane permease ZnuB, a periplasmic-binding protein ZnuA and a cytoplasmic ATPase ZnuC. Low-affinity transporters of the ZIP family, described later in this chapter, such as ZupT, have also been shown to be involved in bacterial zinc uptake. 

Group A streptococci PrtFl/Sfbl, PrtF2, LTA SOF/Sfbll, M3 protein... 

Both proteinaceous and non-proteinaceous analogs have been studied. Examples include a synthetic 20 amino acid adhesin peptide sequence copied from S. mutans and LTA of groups A and B streptococci. The synthetic peptide mimics a S. mutans adhesin that binds a salivary protein on dental surfaces and was shovm to inhibit bacterial adherence to immobilized salivary receptors in vitro. In vivo, this peptide hindered the recolonization by S. mutans on teeth that had been cleared of the... 

Natanson, S., Sela, S., Moses, A. E., Musser, J. M., Caparon, M. G., and Hanski, E. (1995). Distribution of fibronectin-binding proteins among group-A streptococci of different M-types. /. Infect. Dis. 171, 871-878. 

Valentrn-Weigand, P., Grulich-Henn, J., Chhatwal, G. S., Muller-Berghaus, G., Blobel, H., and Preissner, K. T. (1988). Mediation of adherence of streptococci to human endothelial cells by complement S protein (vitronectin). Infect. Ininiun. 56, 2851-2855. 

Armstrong attributed the increased resistance of dentin matrix to proteolysis to the blockage of susceptible sites by covalently bound carbohydrate. Later it became clear that the Maillard reaction induces the formation of covalent bonds (cross-links) between protein molecules, accounting for such resistance as well. The presence of non-degradable matrix proteins inhibits mineral dissolution (Chapter 2). In addition, both brown pigments and cross-linked proteins inhibit the production of extracellular polysaccharides by cariogenic streptococci (Kobayashi et al., 1990). 

Like all examined sulfanilamides, this drug is effective in treating infections caused by streptococci, gonococci, pneumococci, staphylococci, and also colon bacillus. However, about 90% of it binds with proteins in the plasma after oral administration, and it diffuses mostly to tissues and tissue fluids, which makes it the drug of choice for many systemic infections. Synonyms of this drug are gantrisin, fultrxin, sulfazin, sulfolar, and others. 

Mupirocin is not related to any of the sys-temically used antibiotics. It is an inhibitor of bacterial protein synthesis and is especially active against gram-positive aerobic bacteria, e.g. methicillin-resistant S. aureus and group A beta-hemolytic streptococci. Absorption through the skin is minimal. Intranasal application may be associated with irritation of mucous membranes. 

Two other common mechanisms of resistance are known. Some cases of resistance of aerobic gramnegative bacilli to streptomycin are due to mutations in the proteins of the bacterial ribosomes. Streptococci, staphylococci, and Pseudomonadaceae resist aminoglycosides as a result of decreased transport of the aminoglycosides into the bacterial cytosol. 

It is a purified preparation of bacterial protein obtained from (3 hemolytic streptococci. 

It is mainly bacteriostatic and inhibits the growth of gram positive organisms which includes staphylococci, streptococci, pneumococci, C. diphtheriae and B. anthracis. Like erythromycin it act by interfering with protein synthesis. 

Streptokinase is a protein (but not an enzyme in itself) synthesized by streptococci that combines with the proactivator plasminogen. This enzymatic complex catalyzes the conversion of inactive plasminogen to active plasmin. Urokinase is a human enzyme synthesized by the kidney that directly converts plasminogen to active plasmin. Plasmin itself cannot be used because naturally occurring inhibitors in plasma prevent its effects. However, the absence of inhibitors for urokinase and the streptokinase-proactivator complex permits their use clinically. Plasmin formed inside a thrombus by these activators is protected from plasma antiplasmins, which allows it to lyse the thrombus from within. 

Lactic streptococci initiate casein degradation through the action of cell wall-associated and cell membrane-associated proteinases and peptidases. Small peptides are taken into the cell and hydrolyzed to their constituent amino acids by intracellular peptidases (Law and Sharpe 1978). Peptides containing four to seven residues can be transported into the cell by S. cremoris (Law et al. 1976B). S. lactis and S. cremoris have surface-bound peptidases and thus are not totally dependent on peptide uptake for protein use (Law 1979B). Some surface peptidases of S. cremoris are located in the cell membrane, whereas others are located at the cell wall-cell membrane interface (Exterkate 1984). Lactic streptococci have at least six different aminopeptidase activities, and can be divided into three groups based on their aminopeptidase profiles (Kaminogawa et al 1984). 

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