Streptolysin
| Streptolysin O | |||||||
|---|---|---|---|---|---|---|---|
| Identifiers | |||||||
| Organism | |||||||
| Symbol | slo | ||||||
| UniProt | P0C0I3 | ||||||
| |||||||
| Streptolysin S | |||||||
|---|---|---|---|---|---|---|---|
| Identifiers | |||||||
| Organism | |||||||
| Symbol | sagA | ||||||
| UniProt | Q1J7I0 | ||||||
| |||||||
Streptolysins are two hemolytic exotoxins from Streptococcus.[1][2] Types include streptolysin O (SLO; slo), which is oxygen-labile, and streptolysin S (SLS; sagA), which is oxygen-stable.[3]
SLO is part of the thiol-activated cytolysin family.[4] It is hemolytically active only in a reversibly reduced state. It is antigenic, so its antibody antistreptolysin O can be detected in an antistreptolysin O titre.
SLS is stable in the presence of oxygen. It is not antigenic due to its small size. It is sometimes considered a bacteriocin due to similarities in the synthesis pathway.[5]
Streptolysin O
Streptolysin O (SLO; slo), is a bacterial toxin that has four protein domains which is known to make the plasma membranes in animal cells permeable. It does this by creating pore complexes within the membrane by first binding a monomer to the cholesterol found in the target membrane and then forming an oligomeric transmembrane pore.[6] This toxin excreted by a Gram-positive bacteria Streptococcus pyogenes, under the classification of Thiol-activated cytolysin or CDCs. In order for Streptolysin O to work effectively, it needs a significant amount of cholesterol to be present in the target membrane. Unlike other Cholesterol-dependent cytolysins, SLO contains a 60 Amino acid N-terminal domain that makes it easier to identify.
This toxin contains highly antigenic effects which causes it to produce the antibody anti-streptolysin O. Clinically, the presence of these antibodies can indicate a recent Group A streptococcal infection. Streptolysin O is also known to facilitate apoptosis in Keratinocytes. It is able to do this by translocating NAD+ glycohydrolase (SPN) across the target cells membrane. It then removes the N-terminal domain which stops SPN translocation leading to SPN mediated apoptosis.[7]
References
- ^ "streptolysin" at Dorland's Medical Dictionary
- ^ Streptolysin at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
- ^ Sierig G, Cywes C, Wessels MR, Ashbaugh CD (January 2003). "Cytotoxic effects of streptolysin o and streptolysin s enhance the virulence of poorly encapsulated group a streptococci". Infection and Immunity. 71 (1): 446–55. doi:10.1128/IAI.71.1.446-455.2003. PMC 143243. PMID 12496195.
- ^ Billington SJ, Jost BH, Songer JG (January 2000). "Thiol-activated cytolysins: structure, function and role in pathogenesis". FEMS Microbiology Letters. 182 (2): 197–205. doi:10.1111/j.1574-6968.2000.tb08895.x. PMID 10620666.
- ^ Lee SW, Mitchell DA, Markley AL, Hensler ME, Gonzalez D, Wohlrab A, et al. (April 2008). "Discovery of a widely distributed toxin biosynthetic gene cluster". Proceedings of the National Academy of Sciences of the United States of America. 105 (15): 5879–84. doi:10.1073/pnas.0801338105. PMC 2311365. PMID 18375757.
- ^ Abdel Ghani EM, Weis S, Walev I, Kehoe M, Bhakdi S, Palmer M (November 1999). "Streptolysin O: inhibition of the conformational change during membrane binding of the monomer prevents oligomerization and pore formation". Biochemistry. 38 (46): 15204–11. doi:10.1021/bi991678y. PMID 10563803.
- ^ Reglinski, Mark; Sriskandan, Shiranee (2015), "Streptococcus pyogenes", Molecular Medical Microbiology, Elsevier, pp. 675–716, ISBN 978-0-12-397169-2, retrieved 2021-04-28
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