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

N J Belshaw; G Williamson

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

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

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

Authors

N J Belshaw¹, G Williamson

Affiliation

¹ AFRC Institute of Food Research, Norwich, Norfolk, U.K.

PMID: 2049377
DOI: 10.1016/0167-4838(91)90100-e

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aspergillus niger / enzymology
Binding Sites
Catalysis
Cyclodextrins / metabolism*
Glucan 1,4-alpha-Glucosidase / metabolism*
Protein Binding
Spectrophotometry, Ultraviolet
Starch / metabolism*
beta-Cyclodextrins*

Substances

Cyclodextrins
beta-Cyclodextrins
Starch
Glucan 1,4-alpha-Glucosidase
betadex