Hydrolysis of Various Substrates by Two Forms of the Purified Glucoamylase from Rhizopus oryzae

Rhizopus oryzae로 부터 정제(精製)한 두가지형의 Glucoamylase의 각종기질(各種基質)의 가수분해(加水分解)

These experiments were conducted to investigate the substrate specificity, the hydrolysis products on the various carbohydrates and the hydrolysis rate on the various raw starches of the two purified glucoamylase produced by Rhizopus oryzae. Both of the glucoamylases hydrolyzed amylose, amylopectin, glycogen, soluble starch, pullulan, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose and maltooctaose, but did not act on ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, raffinose, sucrose and lactose. When the reaction mixture of glucoamylase and polysaccharides were incubated $37^{\circ}C$for 32 hours, glucoamylase I hydrolyzed amylopectin, soluble starch and amyloses completely, but hydrolyzing glycogen up to only about 88%. Glucoamylase II hydrolyzed the previous four polysaccharides up to about 100%. Both of the glucoamylases produced only glucose for various substrates and did not have any ${\alpha}-glucosyl$ transferase activity. Both of the glucoamylases hydrolyzed raw glutinous rice starch almost complety, wheras they acted on raw potato starch, raw green banana starch, raw arrow root starch, raw corn starch, raw yam starch and raw high amylose corn starch weakly. Glucoamylase II hydrolyzed raw starches at the higher rate than glucoamylase I.

Rhizopus oryzae 가 생산(生産)하는 glucoamylase 의 각종기질(各種基質)에 대(對)한 분해반응(分解反應)을 검토(檢討)하였다. Glucoamylase I 과 II 는 amylose, amylopectin, glycogen, 가용성 전분, pullulan, maltose, maltotriose, maltotetriose, maltopentaose, maltohexaose, maltoheptaose, maltooctaose를 가수분해(加水分解)하였으나, ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, sucrose, raffinose, 젖당은 가수분해(加水分解)하지 못하였다. $37^{\circ}C$, 32시간(時間)의 반응(反應)에서 glucoamylase I 은 amylopectin, 가용성 전분, amylose를 거의 100% 분해하였고 glycogen 만을 88%정도 분해 하였으나, glucoamylase II 는 공시기질(供試基質) 4 종(種)을 거의 100% 분해하였다. Glucoamylase I 과 II 의 반응생성물질(反應生成物質)은 glucose 만이었고 ${\alpha}-glucosyltransferase$ activity는 없었다. Glucoamylase I 과 II 는 생찹쌀 전분을 가장 잘 분해(分解)시키나 생감자 전분, 생미숙 바나나 전분, 생칡 전분, 생참마 전분, raw high amylose corn starch의 분해능(分解能)은 glucoamyase I 에 비(比)하여 생전분(生澱粉)의 분해력(分解力)이 강(强)하였다.