Short Communication

The mutual effects of P. gingivalis and several cystatin species has been investigated. After incubation with P gingivalis culture supernatant, cystatin S, cystatin C and chicken cystatin were truncated from a 14 kDa protein into a polypeptide of approximately 13 kDa. Amino acid sequence analysis of the truncated cystatin S polypeptide revealed that cystatin S was cleaved after Arg-8. All three types of truncated cystatins fully retained their inhibitory activity toward papain. Cystatin S and chicken cystatin partially inhibited proteolytic activity in the culture supernatant of P. gingivalis. Furthermore, cystatin S and chicken cystatin inhibited the growth of R gingivalis in culture to 50% at approximately 1 .