豌豆（Pisum sativum L.）幼苗中三种α-葡萄糖苷酶同工型的部分特性及亚细胞定位
Partial Characterization and Subcellular Localization of Three alpha-Glucosidase Isoforms in Pea (Pisum sativum L.) Seedlings.
作者信息
Beers E P, Duke S H, Henson C A
机构信息
Department of Agronomy, University of Wisconsin, Madison, Wisconsin 53706-1597.
出版信息
Plant Physiol. 1990 Oct;94(2):738-44. doi: 10.1104/pp.94.2.738.
Three isoforms of alpha-glucosidase (EC 3.2.1.20) have been extracted from pea (Pisum sativum L.) seedlings and separated by DEAE-cellulose and CM-Sepharose chromatography. Two alpha-glucosidase isoforms (alphaG1 and alphaG2) were most active under acid conditions, and appeared to be apoplastic. A neutral form (alphaG3) was most active near pH 7, and was identified as a chloroplastic enzyme. Together, the activity of alphaG1 and alphaG2 in apoplastic preparations accounted for 21% of the total acid alpha-glucosidase activity recovered from pea stems. The vast majority (86%) of the apoplastic acid alpha-glucosidase activity was due to alphaG1. The apparent K(m) values for maltose of alphaG1 and alphaG2 were 0.3 and 1.3 millimolar, respectively. The apparent K(m) for maltose of alphaG3 was 33 millimolar. The respective native molecular weights of alphaG1, alphaG2, and alphaG3 were 125,000, 150,000, and 110,000.
已从豌豆（Pisum sativum L.）幼苗中提取出三种α-葡萄糖苷酶（EC 3.2.1.20）同工型，并通过DEAE-纤维素和CM-琼脂糖凝胶色谱法进行分离。两种α-葡萄糖苷酶同工型（αG1和αG2）在酸性条件下活性最高，似乎位于质外体。一种中性形式（αG3）在pH 7附近活性最高，被鉴定为叶绿体酶。质外体制剂中αG1和αG2的活性共同占从豌豆茎中回收的总酸性α-葡萄糖苷酶活性的21%。质外体酸性α-葡萄糖苷酶活性的绝大多数（86%）归因于αG1。αG1和αG2对麦芽糖的表观K(m)值分别为0.3和1.3毫摩尔。αG3对麦芽糖的表观K(m)为33毫摩尔。αG1、αG2和αG3各自的天然分子量分别为125,000、150,000和110,000。
Zotero 插件