title: Inactivation of Vibrio vulnificus hemolysin through mutation of the N- or C-terminus of the lectin-like domain.
abstract: Vibrio vulnificus is an etiological agent causing serious systemic infections in the immunocompromised humans or cultured eels. This species commonly produces a hemolytic toxin consisting of the cytolysin domain and the lectin-like domain. For hemolysis, the lectin-like domain specifically binds to cholesterol in the erythrocyte membrane, and to form a hollow oligomer, the toxin is subsequently assembled on the membrane. The cytolysin domain is essential for the process to form the oligomer. Three-dimensional structure model revealed that two domains connected linearly and the C-terminus was located near to the joint of the domains. Insertion of amino acid residues between two domains was found to cause inactivation of the toxin. In the C-terminus, deletion, substitution or addition of an amino acid residue also elicited reduction of the activity. However, the cholesterol-binding ability was not affected by the mutations. These results suggest that mutation of the C- or N-terminus of the lectin-like domain may result in blockage of the toxin assembly.
authors.affiliation: Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima-Naka, Okayama 700-8530, Japan. miyoshi@pharm.okayama-u.ac.jp
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Miyoshi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Abe
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Senoh
authors.forename: Tamaki
authors.initials: T
authors.lastname: Mizuno
authors.forename: Yoko
authors.initials: Y
authors.lastname: Maehara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakao
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism*; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction; D017434:Protein Structure, Tertiary / Q000235:genetics*; D041261:Vibrio vulnificus / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D006460:Hemolysin Proteins; C073845:hemolysin, Vibrio; D002784:Cholesterol