Comparative Study of the Cyclization Reactions of Three Bacterial Cyclomaltodextrin Glucanotransferases
Open Access
- 1 April 2001
- journal article
- research article
- Published by American Society for Microbiology in Applied and Environmental Microbiology
- Vol. 67 (4), 1453-1460
- https://doi.org/10.1128/aem.67.4.1453-1460.2001
Abstract
The actions of cyclomaltodextrin glucanotransferases (CGTase; EC 2.4.1.19 ) from alkalophilic Bacillus sp. strain A2-5a (A2-5a CGTase), Bacillus macerans ( Bmac CGTase), and Bacillus stearothermophilus ( Bste CGTase) on amylose were investigated. All three enzymes produced large cyclic α-1,4-glucans (cycloamyloses) at the early stage of the reaction, but these were subsequently converted into smaller cycloamyloses. However, the rates of this conversion differed among the three enzymes. The product specificity of each CGTase in the cyclization reaction was determined by measuring the amount of each cycloamylose from CD6 to CD31 (CD n , a cycloamylose with a degree of polymerization of n ). A2-5a CGTase produced 10 times more CD7, while Bmac CGTase produced 34 times more CD6 than other cycloamyloses. Bste CGTase produced 12 and 3 times more CD6 and CD7 than other cycloamyloses, respectively. The substrate specificities of the linearization reactions of CD6, CD7, CD8, and larger cycloamyloses (a mixture of CD22 to CD50) were investigated, and we found that CD7 and CD8 are extremely poor substrates for both hydrolytic and transglycosidic linearization (coupling) reactions while larger cycloamyloses are linearized at a much higher rate. By repeating these cyclization and linearization reactions, the larger cycloamyloses initially produced are converted into smaller cycloamyloses and finally into mainly CD6, CD7, and CD8. These three enzymes also differ in their hydrolytic activities, which seem to accelerate the conversion of larger cycloamyloses into smaller cycloamyloses.Keywords
This publication has 35 references indexed in Scilit:
- Rational design of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 to increase α-cyclodextrin productionJournal of Molecular Biology, 2000
- Crystal structure of amylomaltase from Thermus aquaticus, a glycosyltransferase catalysing the production of large cyclic glucansJournal of Molecular Biology, 2000
- X-ray Structure of Cyclodextrin Glucano-transferase from Alkalophilic Bacillus Sp. 1011. Comparison of Two Independent Molecules at 1.8 Å ResolutionActa Crystallographica Section D-Biological Crystallography, 1996
- Crystal Structure at 2.3 Å Resolution and Revised Nucleotide Sequence of the Thermostable Cyclodextrin Glycosyltransferase fromThermoanaerobacterium thermosulfurigenesEM1Journal of Molecular Biology, 1996
- Genetics of a Novel Starch Utilisation Pathway Present inKlebsiella oxytocaJournal of Molecular Biology, 1996
- Nucleotide Sequence and X-ray Structure of Cyclodextrin Glycosyltransferase from Bacillus circulans Strain 251 in a Maltose-dependent Crystal FormJournal of Molecular Biology, 1994
- The transglycosylation reaction of cyclodextrin glucanotransferase is operated by a Ping‐Pong mechanismFEBS Letters, 1994
- Purification and Characterization of Cyclodextrin Glucanotransferase from an AlkalophilicBacillusSpecies and Transglycosylation at Alkaline pHsBioscience, Biotechnology, and Biochemistry, 1994
- Structure of cyclodextrin glycosyltransferase refined at 2.0 Å resolutionJournal of Molecular Biology, 1991
- The Conversion of Starch to Crystalline Dextrins by the Action of a New Type of Amylase Separated from Cultures of Aerobacillus maceransJournal of the American Chemical Society, 1939