title: Expression, purification, and characterization of human osteoclastic protein-tyrosine phosphatase catalytic domain in Escherichia coli.
abstract: Osteoclastic protein tyrosine phosphatase (PTP-oc) is a structurally unique transmembrane protein tyrosine phosphatase (PTP) that contains only a relatively small intracellular PTP catalytic domain, does not have an extracellular domain, and lacks a signal peptide proximal to the NH2 terminus. The present study reports the expression, purification, and characterization of the intracellular catalytic domain of PTP-oc (ΔPTP-oc). ΔPTP-oc was expressed in Escherichia coli cells as a fusion with a six-histidine tag and was purified via nickel affinity chromatography. When with para-nitrophenylphosphate (p-NPP) as a substrate, ΔPTP-oc exhibited classical Michaelis-Menten kinetics. Its responses to temperature and ionic strength were similar to those of other PTPs. The optimal pH value of ΔPTP-oc is approximately 7.0, unlike other PTPs, whose optimal pH values are approximately 5.0.
authors.affiliation: Department of Orthodontics, School of Stomatology, Jilin University, 1500 Qinghua Road, Changchun 130021, PR China.
authors.forename: Huan
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Edmond H. Fischer Signal Transduction Laboratory, School of Life Sciences, Jilin University, Changchun 130012, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Sui
authors.affiliation: Department of Orthodontics, School of Stomatology, Jilin University, 1500 Qinghua Road, Changchun 130021, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Orthodontics, School of Stomatology, Jilin University, 1500 Qinghua Road, Changchun 130021, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Lin
authors.affiliation: Edmond H. Fischer Signal Transduction Laboratory, School of Life Sciences, Jilin University, Changchun 130012, PR China.
authors.forename: Wannan
authors.initials: W
authors.lastname: Li
authors.affiliation: Edmond H. Fischer Signal Transduction Laboratory, School of Life Sciences, Jilin University, Changchun 130012, PR China.
authors.forename: Shu
authors.initials: S
authors.lastname: Xing
authors.affiliation: School of Life Sciences, Jilin University, Changchun 130012, PR China.
authors.forename: Deli
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Orthodontics, School of Stomatology, Jilin University, 1500 Qinghua Road, Changchun 130021, PR China. Electronic address: humin@jlu.edu.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Hu
authors.affiliation: Edmond H. Fischer Signal Transduction Laboratory, School of Life Sciences, Jilin University, Changchun 130012, PR China. Electronic address: fxq@jlu.edu.cn.
authors.forename: Xueqi
authors.initials: X
authors.lastname: Fu
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007700:Kinetics; D010010:Osteoclasts / Q000737:chemistry / Q000201:enzymology*; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D017027:Protein Tyrosine Phosphatases
keywords: Enzyme kinetics; Escherichia coli; Nickel affinity chromatography; Osteoclastic protein tyrosine phosphatase