Characterization of a recombinant thermostable L: -rhamnose isomerase from Thermotoga maritima ATCC 43589 and its application in the production of L-lyxose and L-mannose.
A putative L-rhamnose isomerase (RhaA) from Thermotoga maritima was purified with a specific activity of 55 U/mg by His-Trap affinity chromatography. The native enzyme was estimated as a 46 kDa tetramer by gel filtration chromatography. The half-lives of the enzyme at 75, 80, 85, 90 and 95°C were 773, 347, 187, 118, and 65 h, respectively, indicating that it is the most thermostable of all RhaAs. Under the optimum conditions of pH 8.0, 85°C, and 1 mM Mn(2+), RhaA with 100 U enzyme/ml converted 500 L-xylulose/l to 225 g/l L-lyxose after 3 h, and converted 500 L-fructose/l to 175 g/l L-mannose after 5 h.
Park
Chang-Su
CS
Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701, South Korea.
Yeom
Soo-Jin
SJ
Lim
Yu-Ri
YR
Kim
Yeong-Su
YS
Oh
Deok-Kun
DK
D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D003067:Coenzymes / Q000378:metabolism; D004795:Enzyme Stability; D006207:Half-Life; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008345:Manganese / Q000378:metabolism; D008358:Mannose / Q000378:metabolism*; D010429:Pentoses / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity; D020124:Thermotoga maritima / Q000201:enzymology*; D013997:Time Factors
D003067:Coenzymes; D010429:Pentoses; D011994:Recombinant Proteins; D008345:Manganese; C043333:lyxose; D019747:Aldose-Ketose Isomerases; C062878:L-rhamnose isomerase; D008358:Mannose