Trehalase: Stereocomplementary Hydrolytic and Glucosyl Transfer Reactions with α- and β-D-Glucosyl Fluoride

Edward J. Hehre, Teruo Sawai, Curtis F. Brewer, Masatoshi Nakano, Takahisa Kanda

Research output: Contribution to journalArticle

54 Scopus citations

Abstract

A new understanding has been obtained of the catalytic capabilities of trehalase, an enzyme heretofore held to be strictly specific for hydrolyzing α,α -trehalose and devoid of transglycosylative ability. Highly purified rabbit renal cortical trehalase and a partly purified Candida tropicalis yeast trehalase were found to utilize both α- and β-D-glucosyl fluoride as substrates. In each case, the reactions were competitively inhibited by α,α -trehalose. Both enzymes catalyzed rapid hydrolysis of α-D-glucosyl fluoride to form β-D-glucose (also, of α,α -trehalose to form equimolar a- and β-D-glucose). In addition, digests of β-D-glucosyl fluoride plus α-D-[14C]-glucopyranose with either trehalase (but not controls of enzyme with -D- [14C] glucopyranose alone) yielded small amounts of radioactive trehalose (α-D-glucopyranosyl a-D-[14C]glucopyranoside) which does not accumulate since it is rapidly hydrolyzed. Trehalase thus catalyzes two stereocomplementary types of glycosylation reactions: (I) -D-glucosyl fluoride (or α,α -trehalose) + H2O→ β-D-glucose + HF (or a-Dglucose); (II) β-D-glucosyl fluoride + a-D-glucopyranose -α,α -trehalose + HF. Such behavior shows that the catalytic groups of trehalase, as recently found for other glycosylases, are functionally flexible. The results illustrate the inadequacy of conventional views of carbohydrase specificity and the rigor, as a basic guiding principle, of the concept that glycoside hydrolases and glycosyltransferases form a class of glycosylases effecting glycosyl/proton interchange.

Original languageEnglish (US)
Pages (from-to)3090-3097
Number of pages8
JournalBiochemistry
Volume21
Issue number13
DOIs
StatePublished - Jun 1982

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Trehalase: Stereocomplementary Hydrolytic and Glucosyl Transfer Reactions with α- and β-D-Glucosyl Fluoride'. Together they form a unique fingerprint.

  • Cite this