Functions of the COOH-terminal region of cyclodextrin glucanotransferase of alkalophilic Bacillus sp. #1011: relation to catalyzing activity and pH stability

K Kimura; S Kataoka; A Nakamura; T Takano; S Kobayashi; K Yamane

doi:10.1016/0006-291x(89)91380-6

Functions of the COOH-terminal region of cyclodextrin glucanotransferase of alkalophilic Bacillus sp. #1011: relation to catalyzing activity and pH stability

Biochem Biophys Res Commun. 1989 Jun 30;161(3):1273-9. doi: 10.1016/0006-291x(89)91380-6.

Authors

K Kimura¹, S Kataoka, A Nakamura, T Takano, S Kobayashi, K Yamane

Affiliation

¹ Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan.

PMID: 2525902
DOI: 10.1016/0006-291x(89)91380-6

Abstract

Cyclodextrin glucanotransferase (beta-CGTase) of alkalophilic Bacillus sp. #1011 degrades starch to mainly beta-cyclodextrin (beta-CD). This enzyme is considered to contain an extra-polypeptide in its COOH-terminal region in addition to its NH2-terminal domain which exhibits the starch-degrading activity. To analyze the functions of this extra-polypeptide in the beta-CGTase, two mutated enzymes, in which DNA regions encoding 10 or 13 amino acids from the COOH-terminus were deleted, were obtained. The mutated enzymes degraded starch to glucose, maltooligosaccharides and alpha-CD, in addition to beta-CD. Furthermore, the pH stability of the mutated enzymes in the alkaline pH range (pH 9-11) was reduced.

MeSH terms

Bacillus / enzymology*
Bacillus / genetics
Enzyme Stability
Escherichia coli / genetics
Glucosyltransferases / genetics
Glucosyltransferases / metabolism*
Hydrogen-Ion Concentration
Kinetics
Plasmids

Substances

Glucosyltransferases
cyclomaltodextrin glucanotransferase