title: Pnserpin: A Novel Serine Protease Inhibitor from Extremophile Pyrobaculum neutrophilum.
abstract: Serine protease inhibitors (serpins) are native inhibitors of serine proteases, constituting a large protein family with members spread over eukaryotes and prokaryotes. However, only very few prokaryotic serpins, especially from extremophiles, have been characterized to date. In this study, Pnserpin, a putative serine protease inhibitor from the thermophilePyrobaculum neutrophilum, was overexpressed inEscherichia colifor purification and characterization. It irreversibly inhibits chymotrypsin-, trypsin-, elastase-, and subtilisin-like proteases in a temperature range from 20 to 100 °C in a concentration-dependent manner. The stoichiometry of inhibition (SI) of Pnserpin for proteases decreases as the temperature increases, indicating that the inhibitory activity of Pnserpin increases with the temperature. SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) showed that Pnserpin inhibits proteases by forming a SDS-resistant covalent complex. Homology modeling and molecular dynamic simulations predicted that Pnserpin can form a stable common serpin fold. Results of the present work will help in understanding the structural and functional characteristics of thermophilic serpin and will broaden the current knowledge about serpins from extremophiles.
authors.affiliation: Department of Cell Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China. zhanghuan1990@yahoo.com.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Cell Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China. feirui@jlu.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Fei
authors.affiliation: Department of Cell Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China. xuebg@jlu.edu.cn.
authors.forename: Baigong
authors.initials: B
authors.lastname: Xue
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China. yushanshan001@aliyun.com.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Yu
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering, Ministry of Education, Jilin University, Changchun 130012, China. zmzhang@jlu.edu.cn.
authors.forename: Zuoming
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Cell Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China. zhongsheng2016@aliyun.com.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhong
authors.affiliation: Department of Cell Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China. gaoyq@jlu.edu.cn.
authors.forename: Yuanqi
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Cell Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China. zhouxl@jlu.edu.cn.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D000071825:Extremophiles / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D055550:Protein Stability; D041543:Pyrobaculum / Q000737:chemistry*; D015203:Reproducibility of Results; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D040681:Structural Homology, Protein; D013696:Temperature
chemical_list: D015842:Serine Proteinase Inhibitors
keywords: Pnserpin; serine protease inhibitor; thermophile