GUAR GUM 分解酸素의 分離 및 그의 性質 = Isolation and Properties of α-Galactosidase which attacks Guar Gum

다국어 초록 (Multilingual Abstract)

1) α-Galactosidase(E.C. 3.2.1.22.α-D-galactoside galactohydrolase) was purified 140-fold from germinated seeds of guar (Cyamopsis tetragondolbus) and the purified eyzyme was shown to be homegeneous on acrylamide gel eletrophoresis and free of related glycosidase activities.
2) Molecular weight of the purified enzyme was estimated to be 25,000 by gel filtration on sephadex G-100. Action of the enzyme toward guaran had a pH optimum 3.8-4.8, activiation energy 7,200 cal/mole and was completely inhibited by H^(++) and p-chloromercuribenzoate, indicationg the presence of an essential SH group. Stability of the enzyme was also studied under various conditions.
3) Examination of the Michaelis constants and relative activities of the enzyme toward various α-D-galactopyranosides showed that aryl α-Dgalactosides and guaran were attacked more readily than oligosaccharides or alkyl α-D-galactosides.
4) The D-g-alactose residues in guaran were completely removed by the purified enzyme, leaving an insoluble β-1,4-mannan. The constant relative activity of the enzyme toward guaran, melibiose and o-nitrophenyl α-D-galactoside through the whole purification procedure and heat denaturation proved that the three substrates were hydrolyzd by the same enzyme.