Complete primary structure of prostatropin, a prostate epithelial cell growth factor

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Bovine brain prostatropin is known as a mitogen for mesenchymal and neuroectodermal cells.
• Its role in prostate epithelial cell growth was previously uncharacterized.

Purpose of the Study:

• To determine the complete amino acid sequence and structure of bovine brain prostatropin.
• To investigate its mitogenic activity on prostate epithelial cells.

Main Methods:

• Edman degradation and peptide cleavage for sequence analysis.
• Fast atom bombardment and tandem mass spectrometry for N-terminal analysis.
• Assay of mitogenic activity on reduced and carboxymethylated prostatropin.

Main Results:

• The major form of prostatropin consists of 154 amino acids with an N-terminal acetyl group.
• Prostatropin shares sequence homology with acidic fibroblast growth factor and class I heparin-binding growth factor.
• Reduced and carboxymethylated prostatropin retains mitogenic activity, indicating disulfide bonds are not essential for function.

Conclusions:

• Bovine brain prostatropin is a potent epithelial cell growth factor.
• It plays a role in supporting prostate hyperplasia and adenocarcinoma.
• This finding expands the known functions of brain-derived growth factors.