Characterization of a thermostable endo-1,5-alpha-L-arabinanase from Caldicellulorsiruptor saccharolyticus.
A recombinant putative glycoside hydrolase from Caldicellulosiruptor saccharolyticus was purified with a specific activity of 12 U mg(-1) by heat treatment and His-Trap affinity chromatography, and identified as a single 56 kDa band upon SDS-PAGE. The native enzyme is a dimer with a molecular mass of 112 kDa as determined by gel filtration. The enzyme exhibited its highest activity when debranched arabinan (1,5-alpha-L-arabinan) was used as the substrate, demonstrating that the enzyme was an endo-1,5-alpha-L-arabinanase. The K (m), k (cat), and k (cat)/K (m) values were 18 mg ml(-1), 50 s(-1), and a 2.8 mg ml(-1) s(-1), respectively. Maximum enzyme activity was at pH 6.5 and 75 degrees C. The half-lives of the enzyme at 65, 70 and 75 degrees C were 2440, 254 and 93 h, respectively, indicating that it is the most thermostable of the known endo-1,5-alpha-L-arabinanases.
Hong
Mi-Ri
MR
Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, South Korea.
Park
Chang-Su
CS
Oh
Deok-Kun
DK
D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002415:Cats; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006094:Gram-Positive Bacteria / Q000201:enzymology*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D011134:Polysaccharides / Q000378:metabolism
D001426:Bacterial Proteins; D011134:Polysaccharides; C030080:araban; D006026:Glycoside Hydrolases; C019713:alpha-N-arabinofuranosidase