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Aspergillus niger lipase: Heterologous expression in Pichia pastoris , molecular modeling prediction and the importance of the hinge domains at both sides of the lid domain to interfacial activation
Author(s) -
Shu Zhengyu,
Duan Mojie,
Yang Jiangke,
Xu Li,
Yan Yunjun
Publication year - 2009
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.147
Subject(s) - pichia pastoris , aspergillus niger , lipase , esterase , catalytic triad , hydrolase , protein engineering , chemistry , protein structure , biochemistry , protein secondary structure , computational biology , recombinant dna , enzyme , active site , biology , gene
Aspergillus niger lipase (ANL) is an important biocatalyst in the food processing industry. However, there is no report of its detailed three-dimensional structure because of difficulties in crystallization. In this article, based on experimental data and bioinformational analysis results, the structural features of ANL were simulated. Firstly, two recombinant ANLs expressed in Pichia pastoris were purified to homogeneity and their corresponding secondary structure compositions were determined by circular dichroism spectra. Secondly, the primary structure, the secondary structure and the three-dimensional structure of ANL were modeled by comparison with homologous lipases with known three-dimensional structures using the BioEdit software, lipase engineering database (http://www.led.uni-stuttgart.de/), PSIPRED server and SwissModel server. The predicted molecular structure of ANL presented typical features of the alpha/beta hydrolase fold including positioning of the putative catalytic triad residues and the GXSXG signature motif. Comparison of the predicted three-dimensional structure of ANL with the X-ray three-dimensional structure of A. niger feruloyl esterase showed that the functional difference of interfacial activation between lipase and esterase was concerned with the difference in position of the lid. Our three-dimensional model of ANL helps to modify lipase structure by protein engineering, which will further expand the scope of application of ANL.