Succinylation of cyclodextrin glycosyltransferase from Thermoanaerobacter sp 501 enhances its transferase activity using starch as donor

A simple modification procedure, the succinylation of amino groups, was sui table to increase the transferase (disproportionation) activity of cyclodex trin glycosyltransferase (CGTase) from Thermoanaerobacter sp. 501 using dif ferent linear oligosaccharides as accepters. On the contrary, the synthesis of cyclodextrins (CDs), the coupling of CDs with oligosaccharides, and the hydrolysis of starch decreased after chemical modification. The degree of succinylation of amino groups (45%) was accurately determined by MALDI-TOF mass spectrometry. The formation of CDs under industrial conditions was ana lyzed for native and succinylated CGTases, showing similar selectivity to a lpha-, beta-, gamma -CD. The acceptor reaction with D-glucose using soluble starch as glucosyl donor was studied at 60 degreesC and pH 5.5. Malto-olig osaccharides (MOS) production was notably higher using the semisynthetic en zyme at different ratios (w/w) starch:D-glucose. Thus, more than 90% of the initial starch was converted into MOS (G2-G7) in 48 h employing a ratio do nor:acceptor 1:2 (w/w). (C) 2001 Elsevier Science B.V. All rights reserved.