PURIFICATION AND CHARACTERIZATION OF ALPHA-D-MANNOSIDASE FROM THE SEEDS OF KAYA, TORREYA-NUCIFERA

Alpha-D-mannosidase was purified from the extract of seeds of Kaya, To rreya nucifera. The purified enzyme had a molecular mass of similar to 3.6 x 10(5) daltons. This enzyme had an optimum pH at 4.5, and was st able at pH between 5.5 and 6.5. This enzyme appeared to be a metal enz yme containing Zn2+. The enzyme hydrolyzed p-nitrophenyl-alpha-D-manno side, methyl-alpha-D-mannoside, alpha-1-->3-mannobiose, and alpha-1--> 6-mannobiose, with K-m of 0.785mM, 0.236M, 2.505 mM, and 0.268 mM, res pectively. The hydrolysis of various alpha-linked mannobioses indicate d that the enzyme hydrolyzes the alpha-mannobioses in the order of alp ha-(1-->2)> -(1-->6)> -(1-->3).