title: A novel bacterial type II l-asparaginase and evaluation of its enzymatic acrylamide reduction in French fries.
abstract: This study reports the identification of a novel bacterial type II l-asparaginase, abASNase2, from Aquabacterium sp. A7-Y. The enzyme contains 319 amino acids and shared 35% identity with Escherichia coli type II l-asparaginase (EcAII), a commercial enzyme trademarked Elspar®that is widely used for medical applications. abASNase2 had high specific activity (458.9U/mg) toward l-asparagine, very low activity toward l-glutamine and d-glutamine and no activity toward d-asparagine. The optimal enzymatic activity conditions for abASNase2 were found to be 50mM Tris-HCl buffer (pH 9.0) at 60°C. It was very stable in the pH range of 7.0-11.0 and exhibited up to 80% relative activity after 2h below 40°C. The Kmand kcatof abASNase2 were 1.8×10-3M and 241.9s-1, respectively. In addition, abASNase2's ability to remove acrylamide from fried potato strips was evaluated. Compared to untreated potato strips (acrylamide content: 0.823±0.0457mg/kg), 88.2% acrylamide was removed in the abASNase2-treated group (acrylamide content: 0.097±0.0157mg/kg). These results indicate that the novel l-asparaginase abASNase2 is a potential candidate for applications in the food processing industry.
authors.affiliation: Key Laboratory of Environmental Microbiology of Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Key Laboratory of Environmental Microbiology of Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors.forename: Ran
authors.initials: R
authors.lastname: Qin
authors.affiliation: Key Laboratory of Environmental Microbiology of Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors.forename: Ding
authors.initials: D
authors.lastname: Li
authors.affiliation: Key Laboratory of Environmental Microbiology of Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors.forename: Kai
authors.initials: K
authors.lastname: Ji
authors.affiliation: Key Laboratory of Environmental Microbiology of Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.affiliation: Key Laboratory of Environmental Microbiology of Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors.forename: Zhongli
authors.initials: Z
authors.lastname: Cui
authors.affiliation: Key Laboratory of Environmental Microbiology of Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China. Electronic address: huangyan@njau.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
mesh_terms: D020106:Acrylamide / Q000378:metabolism*; D001215:Asparaginase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D001419:Bacteria / Q000201:enzymology*; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010802:Phylogeny; D011995:Recombination, Genetic / Q000235:genetics; D011198:Solanum tuberosum / Q000737:chemistry*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D020106:Acrylamide; D001215:Asparaginase
keywords: Aquabacterium sp. A7-Y; Food processing; l-Asparaginase