title: [Expression and biology identification of the human epididymis-specific gene ESC42 in E. coli].
abstract: OBJECTIVE
  To provide materials for the study of the function of ESC42 protein specifically expressed in the human epididymis.
  
  
  METHODS
  The ESC42 gene was amplified from the human epididymis cDNA library by PCR and then cloned into prokaryotic expression vector pGEX-4T-1, expressed and purified by recombinant DNA techniques. The specificity of ESC42 protein was identified by Western blot and MALDI-TOF-MS. The database was searched by Ms-Fit.
  
  
  RESULTS
  The recombinant plasmid expressed a Mr 38 x 10(3) fusion protein in E. coli at a level of 30% of the total protein, and the purity was as high as 99%. The ESC42 protein was identified by ESC42 monoclonal antibody and its molecular weight was 11 978.12, tested by MALDI-TOF-MS. The peptide mass fingerprint analysis showed that the coverage rate of the sequence reached 48% with 100% matching. The motif scan in Prosite database reveal that ESC42 belonged to the beta-defensin family and had antibacterial activity.
  
  
  CONCLUSIONS
  Obtaining high purity of rhESC42 protein may lay a foundation for the study of its functions.
authors.affiliation: Central Laboratory of Yantai Yuhuangding Hospital, Shandong Stem Cell Engineering Research Center, Yantai, Shandong 264000, China. sxfcym@yahoo.com.en
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Shen
authors.forename: Jian-Yuan
authors.initials: JY
authors.lastname: Li
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Wang
authors.forename: Jiang-Nan
authors.initials: JN
authors.lastname: Xue
authors.forename: Qi-Zhi
authors.initials: QZ
authors.lastname: Cao
authors.forename: Pei-Wen
authors.initials: PW
authors.lastname: Lian
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Mei-Na
authors.initials: MN
authors.lastname: Xie
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D003001:Cloning, Molecular; D023082:Defensins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D004822:Epididymis / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D015723:Gene Library; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; C437905:DEFB118 protein, human; D023082:Defensins; D011993:Recombinant Fusion Proteins