PURIFICATION AND CHARACTERIZATION OF THE SURFACE ACTIVE PROTEINS OF BLACK GRAM (PHASEOLUS MUNGO)

Abstract

The surface active globulin from black gram was resolved into 2 components with high foam-forming activity. They were found to be homogeneous by elecrophoresis and ultracentrifugal examinations and had high molecular weights around 100,000 daltons. They were rich in acidic and basic amino acids but low in S amino acids. Heat treatment, proteolysis and treatment with certain inorganic salts such as Cu, and mercurous mercury, group specific reagents P-chloromercury benzoate and N-ethylmalemide (PCMB, NEM) and protein denaturants were found to have an adverse effect, while oxidizing agents had no effect. The free sulfhydryl content was low (3 and 4 .mu.mol/mol), but essential for full manifestation of surface activity. Other purified proteins also needed free sulfhydryl groups.