Structural highlights
Function
[PHLC_CLOP1] Bacterial hemolysins are exotoxins that attack blood cell membranes and cause cell rupture. Constitutes an essential virulence factor in gas gangrene. Binds to eukaryotic membranes where it hydrolyzes both phosphatidylcholine and sphingomyelin. The diacylglycerol produced can activate both the arachidonic acid pathway, leading to modulation of the inflammatory response cascade and thrombosis, and protein kinase C, leading to activation of eukaryotic phospholipases and further membrane damage. Acts on human and mouse erythrocytes, but not on rabbit or horse erythrocytes.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The alpha-toxin produced by Clostridium perfringens is one of the best-studied examples of a toxic phospholipase C. In this study, a nontoxic mutant protein from C. perfringens strain NCTC8237 in which Thr74 is substituted by isoleucine (T74I) has been characterized and is compared with the toxic wild-type protein. Thr74 is part of an exposed loop at the proposed membrane-interfacing surface of the toxin. The mutant protein had markedly reduced cytotoxic and myotoxic activities. However, this substitution did not significantly affect the catalytic activity towards water-soluble substrate or the overall three-dimensional structure of the protein. The data support the proposed role of the 70-90 loop in the recognition of membrane phospholipids. These findings also provide key evidence in support of the hypothesis that the hydrolysis of both phosphatidylcholine and sphingomyelin are required for the cytolytic and toxic activity of phospholipases.
Comparison of a nontoxic variant of Clostridium perfringens alpha-toxin with the toxic wild-type strain.,Vachieri SG, Clark GC, Alape-Giron A, Flores-Diaz M, Justin N, Naylor CE, Titball RW, Basak AK Acta Crystallogr D Biol Crystallogr. 2010 Oct;66(Pt 10):1067-74. Epub 2010, Sep 18. PMID:20944240[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Vachieri SG, Clark GC, Alape-Giron A, Flores-Diaz M, Justin N, Naylor CE, Titball RW, Basak AK. Comparison of a nontoxic variant of Clostridium perfringens alpha-toxin with the toxic wild-type strain. Acta Crystallogr D Biol Crystallogr. 2010 Oct;66(Pt 10):1067-74. Epub 2010, Sep 18. PMID:20944240 doi:10.1107/S090744491003369X
