IMMOBILIZED CRATYLIA-MOLLIS LECTIN AS A POTENTIAL MATRIX TO ISOLATE PLASMA GLYCOPROTEINS, INCLUDING LECITHIN-CHOLESTEROL ACYLTRANSFERASE

A crude seed extract from the native Brazilian forage, Cratylia mollis Mart., and its purified lectin (termed Cra), were found to precipitat e glycoproteins from serum. An affinity column of Cra lectin coupled t o Sepharose CL-4B was prepared and its ability to isolate glycoprotein s from human plasma compared to that of a commercial immobilized lecti n, Concanavalin (Con) A-Sepharose. Although both lectins are of the al pha-D-mannose/alpha-D-glucose binding class, clear differences in the type and amount of serum glycoproteins adsorbed were seen on analysis by denaturing polyacrylamide gel electrophoresis. Similarly, when a se mipurified preparation of the plasma glycoprotein, lecithin-cholestero l acyltransferase (LCAT, EC 2.3.1.43) was applied to the columns some differences were evident; most LCAT was not retained by either matrix but when the bound fractions were eluted and analyzed electrophoretica lly the LCAT isolated by the Cra-Sepharose column was much purer. Thes e findings suggest that immobilized Cra lectin has the potential for u se in studies both to isolate and to characterize certain serum glycop roteins. (C) 1997 Elsevier Science Ltd.