title: Biochemical properties and potential applications of recombinant leucine aminopeptidase from Bacillus kaustophilus CCRC 11223.
abstract: Experiments were carried out to investigate the effects of various factors on the activity and conformation of recombinant leucine aminopeptidase of Bacillus kaustophilus CCRC 11223 (BkLAP) and potential utilization of BkLAP in the hydrolysis of anchovy protein. Optimal temperature and pH of BkLAP were 70 °C and 8.0 in potassium-phosphate buffer, respectively, and the activity was strongly stimulated by Ni(2+), followed by Mn(2+) and Co(2+). Conformational studies via circular dichroism spectroscopy indicated that various factors could influence the secondary structure of BkLAP to different extents and further induce the changes in enzymatic activity. The secondary structure of BkLAP was slightly modified by Ni(2+) at the concentration of 1×10(-4) M, however, significant changes on the secondary structures of the enzyme were observed when Hg(2+) was added to the concentration of 1×10(-4) M. The potential application of BkLAP was evaluated through combination with the commercial or endogenous enzyme to hydrolysis the anchovy protein. Results showed that combining the BkLAP with other enzymes could significantly increase the degree of hydrolysis and amino acid component of hydrolysate. In this regard, BkLAP is a potential enzyme that can be used in the protein hydrolysate industry.
authors.affiliation: Department of Biotechnology, School of Bioscience & Bioengineering, South China University of Technology, Guangzhou 510006, Guangdong, China; E-Mail:  petsyf@126.com.
authors.forename: Yanfei
authors.initials: Y
authors.lastname: Shen
authors.forename: Fanghua
authors.initials: F
authors.lastname: Wang
authors.forename: Dongming
authors.initials: D
authors.lastname: Lan
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D029941:Fish Proteins / Q000378:metabolism*; D005399:Fishes; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007931:Leucyl Aminopeptidase / Q000737:chemistry* / Q000235:genetics; D008970:Molecular Weight; D010957:Plasmids / Q000235:genetics; D011492:Protein Hydrolysates / Q000096:biosynthesis* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D000596:Amino Acids; D029941:Fish Proteins; D011492:Protein Hydrolysates; D011994:Recombinant Proteins; D007931:Leucyl Aminopeptidase