Irpex lacteus の Cellulase の分画と各成分の性質

概要

論文の詳細を見る
A partially purified cellulase preparation from Irpex lacteus was sujected to fractionation by different column chromatographies to make a possible separation of the cellulase component of a C_1-type from that of a C_x-type which might independently exist in the preparation.Gel-filtration of the purified sample on the various kinds of sephadex showed no remarkable separation of components upon elution with 0.1 M acetate buffer at pH 5.0,but gave two major components with 0.1 M pyridine-acetate buffer at pH 6.0 except on Sephadex G-25. The component first eluted on the gel-filtration showed a relatively high saccharifying activity toward CMC as compared with that for Avicel and cellulose powder, whereas the second component had an activity in reverse relation. Cellulose powder column chromatography resolved the partially purified sample into four major components. The second component, named CMCase fraction, eluted with 0.1 M phosphaet buffer at pH 6.7 showed a remarkable sacchrifying activity toward CMCase compared with decrease in its viscosity, and seemed to be of a less random type, and free from β-glucosidase activity. The CMCase fraction hydrolyzed, though slightly, Walseth cellulose, Avicel and cellulose powder in adition to CMC, and produced dominantly cellobiose together with a small amount of glucose. DEAE-Sephadex A-25 column chromatography gave three major components separated completely from each other. The first two of them showed saccharifying activities toward CMC and Avicel, though different in their rates, and the last one, named Avicelase fraction, had a high saccharifying activity for Aviel, Walseth cellulose and cellulose powder. It showed also an appreciably high CMCase activity and free from β-glucosidase activicy. The Avicel fraction also caused a predominant production of cellobiose, accompanying the minor portion of glucose, from these insolble and soluble substrates.The CMCase and Avicelase fractions hydrolyzed, in addition to the above long chain substrates, several celloligosaccharides other than cellobiose in a random fashon and formed all possible products from each oligosaccharide. However, the amount of cellobiose was largest on the hydrolysis of cello-tetraose and -hexaose. Ease with which these cellooligosacchraides were hydrolyzed by the two fractions was in parallel with the degree of polymerization of substrates. p-Nitro-phenyl-β-cellobioside received the hydrolysis to the same dergree for cellotriose, but its anglycon linkage was hydrolyzed more easily by CMCase than by Avicelase whereas its holoside linkage was hydrolized in reverse relation.All the above results suggest that both cellulase fractions would cut off cellobiose residue rather easily from the end of substrates, possibly in a less random mechanism.In addition, it is likely that the cellulase component in the Avicelase fraction would have a C_x nature as well as C_1 in its mode of action and even the cellulase component in the CMCase fraction would have not only a C_x nature but also C_1 nature, although the latter nature is relatively weak but enough to be able to attack the substrates of high crystalline structure such as Avicel.The Avicelase fraction was sharply separated from the CMCase fraction which was eluted following the former on the Sephadex G-100 gel-filtration, indicating that the molecular weight of the former may be smaller than that of the latter.
社団法人日本生物工学会の論文
1965-10-25

Irpex lacteus の Cellulase の分画と各成分の性質

スポンサーリンク

概要

著者

関連論文

スポンサーリンク