Recognition of a human sperm surface protein involved in the progesterone-initiated acrosome reaction by antisera against an endomembrane progesterone binding protein from porcine liver

Mol Cell Endocrinol. 1999 Dec 20;158(1-2):187-93. doi: 10.1016/s0303-7207(99)00173-2.


Antisera against a porcine liver endomembrane progesterone (P4)-binding protein inhibited the P4-initiated acrosome reaction (AR) but not the ionomycin-initiated AR of human sperm. Indirect immunofluorescence studies detected antigen in the sperm head that moved during capacitation from a posterior head region to a midhead region. Moreover, the antisera detected a 44.6 kDa protein in western blots of sperm digitonin extracts. These results suggest that a sperm protein with at least partial homology to the liver endomembrane P4-binding protein, is a putative P4-receptor on the sperm plasma membrane involved in the P4-initiated AR.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acrosome Reaction / physiology
  • Animals
  • Blotting, Western
  • Fluorescent Antibody Technique
  • Humans
  • Immune Sera
  • Liver / metabolism
  • Male
  • Membrane Proteins / immunology
  • Membrane Proteins / metabolism*
  • Progesterone / metabolism*
  • Progesterone-Binding Globulin / immunology
  • Progesterone-Binding Globulin / metabolism*
  • Sperm Capacitation / physiology
  • Sperm Head / metabolism*
  • Spermatozoa / metabolism*
  • Swine


  • Immune Sera
  • Membrane Proteins
  • Progesterone-Binding Globulin
  • Progesterone