α-Mannosidase isolated from in vitro growing panax ginseng C.A. Mayer cells.
Biokhimiya, 56 (2), pp. 314 - 319, (1991)
α-Mannosidase (EC 22.214.171.124) from callus culture of Panax ginseng C. A. Meyer cells was isolated and studied. The homogeneous enzyme was found to be of subunit structure, having Mr about 290 kDa and consisting of four subunits of 70 kDa each. Practically no loss of activity was observed at keeping enzyme in a sodium acetate buffer pH 4.6, containing 3 M ammonium sulfat and zinc cations at +4° C during a year. Purified enzyme had 26.5 U (p-nitrophenyl-α-D-mannopyranoside), pH optimum 4.4—4.7, temperature optimum +55° C (umbelliferyl-α-D-manno-pyranoside). In core pentaccharide (Manα1—)2- 3,6Manβ1-4GlcNAcβ1-4GlcNAclβ of asparagine linked sugar chains of grycoproteins Panax α-mannosidase was shown to split predominantly 1,3-mannosidic linkage thus differing in specificity of Jeack bean enzyme splitting mostly 1,6-bonds. In contrast to Jeack bean enzyme ginseng α-mannosidase does not split 1,2-mannosidic bonds.