Publication Abstract from PubMed
Cyclodextrin glycosyltransferase (CGTase) catalyzes the formation of cyclodextrins from starch. Among the CGTases with known three-dimensional structure, Thermoanaerobacterium thermosulfurigenes CGTase has the highest thermostability. By replacing amino acid residues in the B-domain of Bacillus circulans CGTase with those from T. thermosulfurigenes CGTase, we identified a B. circulans CGTase mutant (with N188D and K192R mutations), with a strongly increased activity half-life at 60 degrees C. Asp188 and Arg192 form a salt bridge in T. thermosulfurigenes CGTase. Structural analysis of the B. circulans CGTase mutant revealed that this salt bridge is also formed in the mutant. Thus, the activity half-life of this enzyme can be enhanced by rational protein engineering.
Improved thermostability of bacillus circulans cyclodextrin glycosyltransferase by the introduction of a salt bridge.,Leemhuis H, Rozeboom HJ, Dijkstra BW, Dijkhuizen L Proteins. 2004 Jan 1;54(1):128-34. PMID:14705029[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
