The α-Mannosidase fromCanavalia ensiformisSeeds: Chemical and Kinetic Properties and Action on Animal Lymphocytes

Abstract
The .alpha.-mannosidase from Canavalia ensiformis was characterized with repect to molecular mass, glycoprotein nature, amino-acid composition, enzymic properties and action on animal cells. The enzyme is composed of two pairs of subunits (molecular mass 44 and 66 kDa) which form a tetramer (220 kDa). The larger subunit is glycosylated, the smaller one is not. Both subunits have similar amino-acid compositions. The larger subunit contains a surplus of alanine, aspartic acid/asparagine, histidine, phenylalanine and tryrosine, the smaller one a surplus of glutamic acid/glutamine, serine and threonine. The enzyme is subject to product inhibition by mannose. It stimulates the proliferation of B-lymphocytes from nude mice.