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Physicochemical studies on delta haemolysin, a staphylococcal cytolytic polypeptide
Author(s) -
Fitton John E.
Publication year - 1981
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(81)81133-7
Subject(s) - citation , chemistry , combinatorics , microbiology and biotechnology , philosophy , stereochemistry , biology , library science , mathematics , computer science
Delta haemolysin is one of a number of extracellular cytolytic polypeptides produced by many isolates of Staphylococcus aureus [ 11. It is heat stable, soluble in both organic solvents (e.g., chloroform: methanol, 2: 1, v/v) and aqueous solutions and is inhibited by phospholipids, fatty acids and serum lipoproteins. The toxin is surface active [2] and exhibits pronounced effects on the membranes of a wide variety of cells and organelles. Recent results suggest that delta haemolysin is a potential tumor promoter at sublytic concentrations [3]. MI estimates have ranged from 5200 to 195 000 and it has been suggested that the toxin exists as a multimeric assembly of identical subunits [4]. The toxin monomer has been shown to consist of 26 amino acid residues, contains no proline, cysteine, tyrosine, histidine or arginine and has an N-terminal formylmethionine residue [.5]. The cytolytic effects of delta toxin and melittin, the 26 amino acid residue surface active toxin isolated from bee venom are similar although distinguishable from the cytolytic effects of Triton X-100 [6,7]. The studies described here were designed to investigate and clarify the conflicting relative molecular mass estimates and to provide information about the conformation of the toxin in free solution and in ‘pseudo membrane’ environments using the techniques of fluorescence spectroscopy and gel filtration enabling a more detailed conformational comparison between delta haemolysin and the extensively studied toxin, melittin to be made.