title: [Identification of M(r)22 000 protein in rat epididymal luminal fluid].
abstract: OBJECTIVE
  To identify the specific protein in the epididymal luminal fluid that may play a role in sperm epididymal maturation or modification on the surface of spermatozoa.
  
  
  METHODS
  We compared the differential protein components in the lumen fluids from the caput and cauda segments of the epididymis of normal rats as well as from the cauda segment of experimental left varicocele (ELV) rats by SDS-PAGE or 2D-electrophoresis. The protein spots of interest were selected for MS identification, and the target proteins further characterized by immuno-blot assay.
  
  
  RESULTS
  MS analysis showed that one of the most prominent proteins, M(r) 22 000, was identical to the phosphatidylethanolamine-binding protein (PBP), and it was further identified as PBP by immuno-blot assay.
  
  
  CONCLUSIONS
  PBPs were present in a variety of molecular forms in the epididymal luminal fluid, including the glycosylated form, and ELV markedly elevated the PBP level in the cauda luminal fluid of the rats. Thus, the association of this molecule with sperm surface modification remains an interest for future investigation.
authors.affiliation: Graduate School, Peking Union Medical College, Beijing 100730, China.
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Qi
authors.forename: Yong-Jie
authors.initials: YJ
authors.lastname: Chang
authors.forename: He-Ming
authors.initials: HM
authors.lastname: Yu
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D030501:Epididymal Secretory Proteins / Q000302:isolation & purification*; D004822:Epididymis / Q000378:metabolism*; D008297:Male; D051381:Rats; D014646:Varicocele / Q000378:metabolism*
chemical_list: D030501:Epididymal Secretory Proteins