Inactivation of Vibrio vulnificus hemolysin through mutation of the N- or C-terminus of the lectin-like domain

• Published in: Toxicon (Oxford) Vol. 57; no. 6; pp. 904 - 908
• Main Authors: Miyoshi, Shin-ichi, Abe, Yuki, Senoh, Mitsutoshi, Mizuno, Tamaki, Maehara, Yoko, Nakao, Hiroshi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-05-2011; Elsevier
• Subjects: amino acids; Animal poisons toxicology. Antivenoms; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biological and medical sciences; Blotting, Western; Cell Membrane - metabolism; Cell-free translation; cholesterol; Cholesterol - metabolism; eel; erythrocytes; Erythrocytes - metabolism; etiological agents; Hemolysin; Hemolysin Proteins - genetics; Hemolysin Proteins - metabolism; hemolysis; immunocompromised population; Medical sciences; Mutagenesis; mutation; Mutation - genetics; Polymerase Chain Reaction; Protein Structure, Tertiary - genetics; Site-directed mutagenesis; Toxicology; Vibrio vulnificus; Vibrio vulnificus - chemistry; Hemolysin; Cell-free translation; Site-directed mutagenesis; Vibrio vulnificus; Lectin; Mutagenesis; Bacteria; Vibrionaceae; Mutation; Inactivation; Genetic translation
• ISSN: 0041-0101; 1879-3150
• DOI: 10.1016/j.toxicon.2011.03.013

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.