Title
Amylomaltase of Pyrobaculum aerophilum IM2 produces thermoreversible starch gels
Author
TNO Kwaliteit van Leven TNO Voeding
Kaper, T.
Talik, B.
Ettema, T.J.
Bos, H.
van der Maarel, M.J.E.C.
Dijkhuizen, L.
Publication year
2005
Abstract
Amylomaltases are 4-alpha-glucanotransferases (EC 2.4.1.25) of glycoside hydrolase family 77 that transfer alpha-1,4-linked glucans to another acceptor, which can be the 4-OH group of an alpha-1,4-linked glucan or glucose. The amylomaltase-encoding gene (PAE1209) from the hyperthermophilic archaeon Pyrobaculum aerophilum IM2 was cloned and expressed in Escherichia coli, and the gene product (PyAMase) was characterized. PyAMase displays optimal activity at pH 6.7 and 95°C and is the most thermostable amylomaltase described to date. The thermostability of PyAMase was reduced in the presence of 2 mM dithiothreitol, which agreed with the identification of two possible cysteine disulfide bridges in a three-dimensional model of PyAMase. The kinetics for the disproportionation of malto-oligosaccharides, inhibition by acarbose, and binding mode of the substrates in the active site were determined. Acting on gelatinized food-grade potato starch, PyAMase produced a thermoreversible starch product with gelatin-like properties. This thermoreversible gel has potential applications in the food industry. This is the first report on an archaeal amylomaltase. Copyright © 2005, American Society for Microbiology. All Rights Reserved.
Subject
Food technology
Escherichia coli
Gels
Glucose
Mathematical models
pH effects
Starch
Achaeal amylomaltase
Amylomaltase
Binding mode
Pyrobaculum aerophilum IM2
Enzyme kinetics
4alpha glucanotransferase
Acarbose
Cysteine
Disulfide
Dithiothreitol
Gelatin
Gene product
Glucan
Glucose
Glycosidase
Hydroxyl group
Oligosaccharide
Potato starch
Starch
Enzyme
Archean
Chemical reaction kinetics
Enzyme active site
Enzyme activity
Enzyme inhibition
Enzyme substrate complex
Escherichia coli
Food industry
Gene expression
Heat sensitivity
Molecular cloning
Nonhuman
Pyrobaculum
Pyrobaculum aerophilum
Thermostability
Binding Sites
Cloning, Molecular
Enzyme Stability
Escherichia coli
Food Industry
Gels
Glycogen Debranching Enzyme System
Heat
Kinetics
Pyrobaculum
Starch
Archaea
Escherichia coli
Pyrobaculum aerophilum
Solanum tuberosum
To reference this document use:
http://resolver.tudelft.nl/uuid:24791fd0-5128-42ef-a138-aa58bf4c4471
DOI
https://doi.org/10.1128/aem.71.9.5098-5106.2005
TNO identifier
238663
ISSN
0099-2240
Source
Applied and Environmental Microbiology, 71 (71), 5098-5106
Document type
article