Rekombinant (r-) soyasitatinin papaine olan inhibitörü aktivitesi karakterize edilerek yumurta beyazı sistatin ile karşılaştırılmıştır. E.coli de sentez edilen r-soyasistatin 4 phenyl-Sepharose ve DEAE kolonları rekombinant protein olarak 4.33 kat saflaştırılmıştır. İsoelektirik fokus jeli ile papain ve r-soyasistatin arasındaki spesifik interaksiyon tespit edilmiştir. Papain ve r-soyasistatinin bir kompleks oluşturduğu ve bu kompleksin pI si sistatin ve papain pI lar arasında çözündüğü tespit edilmiştir. Her iki sistatinde geniş bir pH aralığında (pH 4-10) stabilite göstermiş ve soyasistatinin termal stabiliteside yumurta beyazı sistatine benzer bulunmuştur test edilen sıcaklıklarda (0-100 0C). r-Soyasistatinin papaine karşı olan inhibitör aktivitesi yumurta beyazı sistatine benzer bulunmuştur.

Recombinant (r-) soyacystatin was characterized for their inhibitory activity against papain and compared to egg white cystatin. r-Soyacystatin expressed in E. coli was purified 4.33 fold as a recombinant protein with phenyl-Sepharose and DEAE. Egg white cystatin was purified by using affinity chromatography on CM-papain-Sepharose. The specific interaction of r-soyacystatin and papain was detected on isoelectric focusing gel. Papain and r-soyacystatin formed a complex and the complex was resolved in between pIs of cystatins and papain. Both cystatins showed high stability at the wide pH range (pH 4-10), and the thermal stability of soyacystatin was comparable at the temperature range (0-100 0C). The r-soyacystatin exhibited papain-like protease inhibition activity comparable to that of the egg white cystatin, which could inhibit papain.