Immobilized Cratylia mollis lectin as a potential matrix to isolate plasma glycoproteins, including lecithin-cholesterol acyltransferase

Abstract

A crude seed extract from the native Brazilian forage, Cratylia mollis Mart., and its purified lectin (termed Cra), were found to precipitate glycoproteins from serum. An affinity column of Cra lectin coupled to Sepharose CL-4B was prepared and its ability to isolate glycoproteins from human plasma compared to that of a commercial immobilized lectin, Concanavalin (Con) A-Sepharose. Although both lectins are of the alpha-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 semipurified preparation of the plasma glycoprotein, lecithin-cholesterol 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 electrophoretically the LCAT isolated by the Cra-Sepharose column was much purer. These findings suggest that immobilized Cra lectin has the potential for use in studies both to isolate and to characterize certain serum glycoproteins. (C) 1997 Elsevier B.V.