β-环糊精与葡糖淀粉酶颗粒淀粉结合结构域的相互作用

Interaction of beta-cyclodextrin with the granular starch binding domain of glucoamylase.

作者信息

Belshaw N J, Williamson G

机构信息

AFRC Institute of Food Research, Norwich, Norfolk, U.K.

出版信息

Biochim Biophys Acta. 1991 May 30;1078(1):117-20. doi: 10.1016/0167-4838(91)90100-e.

DOI:10.1016/0167-4838(91)90100-e

PMID:2049377

Abstract

The granular starch binding domain of glucoamylase 1 (EC 3.2.1.3 1,4-alpha-D-glucan glucohydrolase) binds two molecules of beta-cyclodextrin, with a dissociation constant (Kd) for the second ligand of 1.68 microM. The catalytic domain showed no interaction with beta-cyclodextrin. Beta-cyclodextrin competitively inhibited the adsorption of the binding domain onto granular starch with an inhibition constant (Ki) of 11.0 +/- 1.9 microM. The results show that beta-cyclodextrin binds to the binding domain of glucoamylase at the same site(s) as granular starch.

摘要

葡糖淀粉酶1（EC 3.2.1.3，1,4-α-D-葡聚糖葡糖水解酶）的颗粒淀粉结合结构域可结合两分子的β-环糊精，第二个配体的解离常数（Kd）为1.68微摩尔。催化结构域与β-环糊精无相互作用。β-环糊精竞争性抑制结合结构域在颗粒淀粉上的吸附，抑制常数（Ki）为11.0±1.9微摩尔。结果表明，β-环糊精与葡糖淀粉酶的结合结构域在与颗粒淀粉相同的位点结合。