Structural studies on rat prostatic binding protein. The primary structure of component C1 from subunit F

Area of Science:

• Biochemistry
• Molecular Biology
• Proteomics

Background:

• Prostatic binding protein (PBP) is a major secretory glycoprotein in the rat ventral prostate.
• Component C1 is the polypeptide specific for subunit F of PBP.

Purpose of the Study:

• To determine the complete amino acid sequence of component C1.
• To elucidate the structural characteristics of this prostatic binding protein subunit.

Main Methods:

• Manual Edman degradation was performed on intact component C1.
• Peptide fragments were generated using trypsin, chymotrypsin, thermolysin, and Staphylococcus aureus protease.
• Fragments were isolated and sequenced from 14C-labeled S-carboxamidomethylated component C1.

Main Results:

• The amino acid sequence of component C1 was established, comprising 88 amino acids.
• The molecular weight of component C1 was determined to be 10246 Da.
• Component C1 is an acidic polypeptide with 17 acidic residues and three cysteine residues.
• Analysis revealed highly polar regions (residues 17-27 and 37-47) and two hydrophobic segments in the C-terminal region.

Conclusions:

• The primary structure of rat prostatic binding protein component C1 has been fully elucidated.
• The determined sequence provides insights into the molecular properties and potential functional domains of component C1.
• Structural features such as acidic residues, cysteine distribution, polar, and hydrophobic regions offer clues to its role in prostatic binding protein.