from rat liver; releases alpha1-2, alpha1-3, alpha1-6 linked residues from oligosaccharide substrates; end product of reaction is Manalpha1-3(Manalpha1-6)Manbeta1-4GlcNAc; MW 110 kDa; inhibited by EDTA, Zn++ & Cu++, swainsonine & 1-deoxymannojirimycin