119th General Meeting of the KCS

Type Poster Presentation
Area 생명화학
Room No. 포스터발표장
Time 4월 21일 (금요일) 13:00~14:30
Code BIO.P-303
Subject Characterization and Immobilization of a novel esterase (LCK37) from Leuconostoc citreum
Authors Wang Ying, 김두헌1,*
숙명여자대학교 화학과, Korea
1숙명여자대학교 이과대학 화학과, Korea
Abstract A recombinant carboxylesterase (LCK37) from Leuconostoc citreum was cloned, over-expressed in Escherichia coli and characterized using biochemical methods. Sequence analysis of LCK37 revealed a putative catalytic triad (Ser170, Asp269 and His301). Based on phylogenetic tree analysis, it can be concluded that LCK37 is a member of new enzyme family with conserved catalytic motif GESSG. Biochemical properties of LCK37 were performed using mass spectrometry, circular dichroism (CD), fluorescence, gel filtration, kinetics, activity staining and pH indicator-based colorimetric assays. Two interesting mutations (L107A and W228A) completely lost their activities towards short-chain p-nitrophenyl (pNP) esters. Cross-linked enzyme aggregates (CLEAs) of LCK37 were prepared by precipitating the enzyme with ammonium sulfate and subsequent cross-linking with glutaraldehyde. Furthermore, Hybrid magnetic cross-linked enzyme aggregates (HM-CLEAs) of LCK37 were developed by co-aggregation of enzyme aggregates with magnetite nanoparticles and subsequent chemical cross-linking with glutaraldehyde. Remarkable stability and reusability of the HM-CLEAs of LCK37, highlight its potential as a biocatalyst in the pharmaceutical and chemical industries.
E-mail yingaabb@yahoo.com