ANEW Pronase Inducible Lectin in Human serum

This investigation was aimed at exploring the possibility to generate defense molecules, such as lectins and phenoloxidase in human serum upon treatment with various exogenous proteases and detergents in vitro. Generation of phenoloxidase and lectin activity was detected, for the first time, upon treatment of human serum with exogenous elicitors. The lectin molecules generated in pronase-treated human serum was successfully isolated by a single step lectin affinity chromatography using concanavalin A- Sepharose 4B as affinity matrix and 200 mM, mannose in tris-HCl buffer (100 mM, pH 8.5) as an ideal eluant. Analyses of the isolated lectin in native PAGE and FPLC revealed that this lectin in active state contains only a single protein fraction with an estimated molecular mass of 6 kDa. The MALDI-TOF MS analysis established its purity with a molecular weight estimate of 6.5 kDa. All these salient features of this lectin clearly indicate that it is a novel humoral lectin generated anew in human serum upon proteolytic action of pronase on certain serum components.