Autolysins involved in conformation-dependent fibronectin binding to dry-fixed Clostridium perfringens

Riyo Aono, Kanako Watanabe-Okabe, Yasuo Hitsumoto, Seiichi Katayama and Nozomu Matsunaga

Summary The pathogen Clostridium perfringens exploits fibronectin (Fn) to mediate adhesion to collagen. Our previous study reported that Fn under low ionic strength (l-Fn) bound significantly to dry-fixed C. perfringens cells compared with Fn under high ionic strength (h-Fn), and that C. perfringens autolysin (Acp) bound to Fn under moderate ionic strength (m-Fn). Our previous studyand this study revealed that m-Fn bound to recombinant Acp C-terminal catalytic domain (rAcpCD) and to rAcpCD plus eight cell wall-binding repeats (rAcpCWB3-10+CD) but not to recombinant six cell wall-binding repeats. l-Fn binding to rAcpCWB3-10+CD exhibited saturable binding and reached a plateau at a low concentration. That of m-Fn exhibited linear, unsaturated binding across all concentration tests. That of h-Fn exhibited an attenuated concentration dependency with reduced slope. Moreover, the binding pattern of Fn to dry-fixed C. perfringens cells was also similar. However, all three Fn showed saturable binding to rAcpCD and reached a plateau at a low concentration. These results pointed to a possibility that the binding of Fn to dry-fixed C.perfringens cells involves AcpCD + cell wall-binding repeats.

Int J Anal Bio-Sci

生物試料分析科学会

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