%0 Journal Article
%T Purification and properties of recombinant extremely thermostable and acid-stable amylase<br>重组超耐热酸性α-淀粉酶的分离纯化及其性质研究
%A LI Hui
%A GUO Jian-qiang YUE Li-li LI Yun-min JIAO Qing-hua
%A <br>李辉
%A 郭建强
%A 岳丽丽
%A 李运敏
%A 矫庆华
%J 微生物学报
%D 2005
%I 
%X Extremely thermostable and acid-stable a-amylase produced by Pichia pastoris GS115/pPIC9K-Amy-228 was purified to electrophoretic homogeneity by the steps of ultrafiltration and PAGE. Purification of about 11.7 fold was achieved with an overall yield of 29.8%. Its molecular weight was estimated to be about 55kD by SDS-PAGE. The isoelectric point was 5.0 (room temperature). Michaelis constant of the enzyme for soluble starch was 1.12g/L. The carbohydrate content was 15.4% by the phenol-sulfuric acid method. The optimum temperature and pH of the enzyme activity were 95 degrees C and 4.5 respectively. The enzyme activity was stable under room temperature in the pH rang of 4.0 - 7.0 for 48 hours. About 60% of the initial enzyme activity was measured after 1h of incubation at 110 degrees C. The activity was strongly inhibited by Fe2+, Cr2+ and Cu2+, While Ca2+ had no effect on it. DTT and EDTA had no effect on the activity.
%K 超耐热酸性α-淀粉酶
%K 纯化
%K 性质
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=A3C6BA55AB623B90FA9104CFFC826F3C&aid=CA9C54F0AC752599&yid=2DD7160C83D0ACED&vid=94E7F66E6C42FA23&iid=E158A972A605785F&sid=4002B7787911C73B&eid=64808317C39DF331&journal_id=0001-6209&journal_name=微生物学报&referenced_num=13&reference_num=15