Penicillium sp. の産生するexo-β-glucosaminidaseの精製と性質

概要

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xo-β-glucosaminidase from penicillium sp. No.CC6-7 strain was highly purified by ultra-filtration, chromatographies twice on CM-Toyopearl 650M, and gel-filtration on Sephacry S-200. The purified enzyme preparation gave one protein band by Native-PAGE and SDS-PAGE. The molecular weight of the enzyme was estimated to be 98,000 by SDS-PAGE. The optimum pH and the optimum temperature was 5.0 and 55℃, respectively. The enzyme was fairly stable at a pH range of 5.0〜8.5 after treatment at 40℃ for 3hr, and 6.0〜8.5 at 40℃ for 24hr. The thermal stability range of the enzyme was below 44℃ after treatment at pH 6.0 for 30min and below 36℃ at pH 6.0 for 3hr. The hydrolysis product from chitosan by the purified enzyme was only glucosamine throughout the entire course of hydrolysis. The purified enzyme produced also only glucosamine from chitooligosaccharides. The Km value of the enzyme for chitooligosaccharides and these alcohols became smaller with a highter degree of polymerization, and the Vmax value became larger with a smaller degree of polymerization. The enzyme was innactivately completely with 1mM hg^2+, Ag^+ and N-bromosuccinimide, highly with 1mM Co^2+, dithiothreitol and iodine, and moderately with 1mM Fe^3+ and Cu^2+.
実践女子大学の論文
2005-03-25