CHITOVIBRIN - A CHITIN-BINDING LECTIN FROM VIBRIO-PARAHEMOLYTICUS

A novel 134 kDa, calcium-independent chitin-binding lectin, ''chitovib rin'', is secreted by the marine bacterium Vibrio parahemolyticus, ind ucible with chitin or chitin-oligomers, Chitovibrin shows no apparent enzymatic activity but exhibits a strong affinity for chitin and chito -oligomers > dp9. The protein has an isoelectric pH of 3.6, shows ther mal tolerance, binds chitin with an optimum at pH 6 and is active in 0 -4M NaCl. Chitovibrin appears to be completely different from other re ported Vibrio lectins and may function to bind V. parahemolyticus to c hitin substrates, or to capture or sequester chito-oligomers. It may b e a member of a large group of recently described proteins in Vibrios related to a complex chitinoclastic (chitinivorous) system.