Cloning and characterization of an exoinulinase from Bacillus polymyxa |
| |
| Authors: | Kwon Hyun-Ju Jeon Sung-Jong You Dong-Ju Kim Kwang-Hyeon Jeong Yong-Kee Kim Young-Hee Kim Young-Man Kim Byung-Woo |
| |
| Institution: | (1) Mitsubishi Kagaku Institute of Life Sciences, Tokyo, 194-8511, Japan;(2) The Special Division for Human Life Technology, National Institute of Advanced Industrial Science and Technology (Kansai), Osaka, 563-8577, Japan;(3) Department of Microbiology, Graduate School, Dongeui University, Pusan, 614-714, Korea;(4) Department of Food Science and Nutrition, Graduate School, Dongeui University, Pusan, 614-714, Korea |
| |
| Abstract: | A gene encoding an exoinulinase (inu) from Bacillus polymyxa MGL21 was cloned and sequenced. It is composed of 1455 nucleotides, encoding a protein (485 amino acids) with a molecular mass of 55 522 Da. Inu was expressed in Escherichia coli and the His-tagged exoinulinase was purified. The purified enzyme hydrolyzed sucrose, levan and raffinose, in addition to inulin, with a sucrose/inulin ratio of 2. Inulinase activity was optimal at 35°C and pH 7, was completely inactivated by 1 mM Ag+ or Hg2+. The K
m and V
max values for inulin hydrolysis were 0.7 mM and 2500  M min–1 mg–1 protein. The enzyme acted on inulin via an exo-attack to produce fructose mainly. |
| |
| Keywords: | Bacillus polymyxa exoinulinase inulin nucleotide sequence |
| 本文献已被 PubMed SpringerLink 等数据库收录！ |
|
