Purification and biochemical characterization of novel acidic chitinase from Paenicibacillus barengoltzii.
The novel chitinase (PbChi67) from the marine bacterium Paenicibacillus barengoltzii CAU904 was purified and biochemically characterized. PbChi67 was purified to apparent homogeneity with 10.2 fold purification and 8.0% recovery yield. The molecular mass of the enzyme was 67.0kDa by SDS-PAGE and 67.9kDa by gel filtration, respectively. PbChi67 was most active at pH 3.5 and was stable within pH 3.0-9.0. The optimal temperature of PbChi67 was 60°C and it was stable up to 55°C with a thermal denaturing half-life of 43min at 65°C. The enzyme exhibited strict substrate specificity towards colloidal chitin and glycol chitin but showed no or trace activities towards other tested substrates. The Km and Vmax values of PbChi67 for colloidal chitin and glycol chitin were 3.35mg/mL and 17.1μmol/min/mg, and 2.66mg/mL and 15.0μmol/min/mg, respectively. PbChi67 hydrolyzed colloidal chitin to yield N-acetyl chitooligosaccharides (COSs) with degree of polymerization (DP) of 2-4 at the initial hydrolysis stage, indicating that it is an endo-type chitinase. These properties make the enzyme as a good candidate for recycling of chitin materials.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Xing
X
Fu
Bioresource Utilization Laboratory, College of Engineering, China Agricultural University, Beijing 100083, China.
Qiaojuan
Q
Yan
Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Jing
J
Wang
Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: ysq@cau.edu.cn.
Shaoqing
S
Yang
Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: zhqjiang@cau.edu.cn.
Zhengqiang
Z
Jiang
D000595:Amino Acid Sequence; D002688:Chitinases / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D056507:Paenibacillus / Q000201:enzymology*; D010455:Peptides / Q000737:chemistry; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors
D010455:Peptides; D002688:Chitinases
Characterization; Chitinase; Paenicibacillus barengoltzii