Alpha-fetoprotein derived synthetic peptides: assay of an estrogen-modifying regulatory segment

Mol Cell Endocrinol. 1996 Apr 19;118(1-2):15-23. doi: 10.1016/0303-7207(96)03762-8.


This study describes the estrogen bioassay of a synthetic peptide fashioned after an amino acid sequence from human alpha-fetoprotein (HAFP). The synthetic peptide (P149), modeled after a portion of the estrogen binding pocket of rat/human AFP chimeras, was produced via F-MOC solid phase chemistry. Bioassay of P149 in the estrogen-sensitive immature rodent uterus demonstrated an anti-estrogenic (40-50% inhibitory) activity in the 23 h but not the 3-4 h uterine response. In contrast to purified HAFP, incubation of the peptide with estrogen was not a prerequisite for inhibitory activity. The estrogen-dependent increase in uterine thrombin and tissue factor, as determined by an enzymatic esterase assay, was inhibited by 30% in rat uterine cytosols. In an in vitro bioassay of estrogen-induced focus formation in MCF-7 human breast cancer cultures, focus development was inhibited by 70% following peptide exposure. The mechanism of the AFP-derived peptide inhibition of estrogen-dependent growth remains to be determined.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Estradiol / pharmacology*
  • Female
  • Humans
  • Mice
  • Molecular Sequence Data
  • Peptides / analysis
  • Peptides / chemical synthesis
  • Pregnancy
  • Rats
  • Rats, Wistar
  • Tumor Cells, Cultured
  • Uterus / drug effects
  • Uterus / metabolism
  • alpha-Fetoproteins / analysis*
  • alpha-Fetoproteins / chemical synthesis


  • Peptides
  • alpha-Fetoproteins
  • Estradiol