Abstract
1) Three ${\beta}-1$, 4-mannanases were isolated from germinated guar bean through extraction, ammonium sulfate fractionation, column chromatography on cellulose derivatives and gel filltration on Sephadex G-100. They were designated as ${\beta}-1$, 4-mannanase A,B and C, respectively, in the order of isolation. 2) These enzymes were different in several aspects such as pH optimum, effect of metal ions, adsorbability on cellulose derivatives, molecular weight, Michaelis constant toward reduced ivory nut mannan A, mode of action and extent of hydrolysis of the mannan. 3) ${\beta}-1$, 4-Mannanases A and C were proposed to be two different endo-enzymes of random-splitting type producing a series of oligosaccharides from ${\beta}-1$, 4-mannans. ${\beta}-1$, 4-Mannanase B was suggested to be possibly an exe-type enzyme catalyzing a stepwise splitting from the non-reducing end of ${\beta}-1$, 4-mannans to produce mannose. 4) Guaran was subjected to hydrolysis by the purified enzymes and the consequence was discussed in connection with structural requirements of the enzymes toward substituted ${\beta}-1$, 4-mannans and their role in germinating guar seeds.
(1) 콩과 식물인 guar (Cyamopsis tetragonolobus)의 발아종자(發芽種子)에서 세 가지의 다른 다당류가수분해효소(多糖類加水分解酵素)인 ${\beta}-1$, 4-mannanase A,B,C 를 추출(抽出), 유안염석(硫安鹽析), 이온교환(交換)크로마토그래휘 및 젤여과법(濾過法)에 의하여 분리(分離), 정제(精製)하였다. (2) 이들 효소(酵素)는 작용최적(作用最適) pH, 급속이온의 영향, 분자량(分子量), ior nut mannan A에 대한 Michaelis 항수(恒數), 가수분해(加水分解)의 한도(限度) 및 생성물등(生成物等) 여러 가지 점(點)에서 다르다. (3) ${\beta}-1$, 4-Mannanase A 와 C 는 기질(基質)인 ${\beta}-1$, 4-mannanase 에 random으로 작용(作用)하여 과당류(寡糖類)를 생성(生成)하는 endo형(型) 효소(酵素)임이 밝혀졌다. 한편 ${\beta}-1$, 4-mannanase B 는 같은 기질(基質)의 비환원말단기(非還元末端基)로 부터 수차로 작용(作用)하여 단당류(單糖類)를 생성(生成)하는 exo형(型) 효소(酵素)로 추리(推理)된다. (4) Guar 종자중(種子中)의 galactomannan 인 guaran에 이들 정제효소(精製酵素)를 작용(作用)시킨 결과(結果)로부터 기질(基質)의 구조(構造) 및 guar 종자(種子)의 발아중(發芽中)에 가지는 역할(役割)과 관련시켜 논의(論議)하였다.