title: Characterization of an acidic chitinase from seeds of black soybean (Glycine max (L) Merr Tainan No. 3).
abstract: Using 4-methylumbelliferyl-β-D-N,N',N″-triacetylchitotrioside (4-MU-GlcNAc3) as a substrate, an acidic chitinase was purified from seeds of black soybean (Glycine max Tainan no. 3) by ammonium sulfate fractionation and three successive steps of column chromatography. The purified chitinase was a monomeric enzyme with molecular mass of 20.1 kDa and isoelectric point of 4.34. The enzyme catalyzed the hydrolysis of synthetic substrates p-nitrophenyl N-acetyl chitooligosaccharides with chain length from 3 to 5 (GlcNAcn, n = 3-5), and pNp-GlcNAc4 was the most degradable substrate. Using pNp-GlcNAc4 as a substrate, the optimal pH for the enzyme reaction was 4.0; kinetic parameters Km and kcat were 245 µM and 10.31 min-1, respectively. This enzyme also showed activity toward CM-chitin-RBV, a polymer form of chitin, and N-acetyl chitooligosaccharides, an oligomer form of chitin. The smallest oligomer substrate was an N-acetylglucosamine tetramer. These results suggested that this enzyme was an endo-splitting chitinase with short substrate cleavage activity and useful for biotechnological applications, in particular for the production of N-acetyl chitooligosaccharides.
authors.affiliation: Department of Food and Nutrition, Providence University, Taichung, Republic of China (Taiwan).
authors.forename: Ya-Min
authors.initials: YM
authors.lastname: Chang
authors.affiliation: Department of Food and Nutrition, Providence University, Taichung, Republic of China (Taiwan).
authors.forename: Li-Chun
authors.initials: LC
authors.lastname: Chen
authors.affiliation: Department of Food and Nutrition, Providence University, Taichung, Republic of China (Taiwan).
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Department of Food Science, Central Taiwan University of Science and Technology, Taichung, Republic of China (Taiwan).
authors.forename: Chui-Liang
authors.initials: CL
authors.lastname: Chiang
authors.affiliation: Department of Food and Nutrition, Providence University, Taichung, Republic of China (Taiwan).
authors.forename: Chen-Tien
authors.initials: CT
authors.lastname: Chang
authors.affiliation: Department of Food and Nutrition, Providence University, Taichung, Republic of China (Taiwan).
authors.forename: Yun-Chin
authors.initials: YC
authors.lastname: Chung
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D002686:Chitin / Q000737:chemistry / Q000378:metabolism; D002688:Chitinases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D006923:Hymecromone / Q000031:analogs & derivatives / Q000378:metabolism; D008970:Molecular Weight; D009844:Oligosaccharides / Q000378:metabolism; D012639:Seeds / Q000201:enzymology*; D013025:Glycine max / Q000201:enzymology*; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D009844:Oligosaccharides; D002686:Chitin; C025158:4-methylumbelliferyl 2-acetamido-2-deoxy-beta-D-glucopyranoside; D006923:Hymecromone; D002688:Chitinases; D000117:Acetylglucosamine