Molecular insights into substrate specificity of prostate specific antigen through structural modeling

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• The established role of Prostate Specific Antigen (PSA) as a prostate cancer biomarker.
• The largely unknown physiological function of PSA's serine protease activity in prostate pathobiology and carcinogenesis.

Purpose of the Study:

• To investigate the substrate binding and recognition mechanisms of PSA's catalytic site.
• To explore the potential of PSA's enzymatic activity in prostate cancer initiation and progression.
• To validate molecular docking insights through experimental synthesis and assays.

Main Methods:

• Molecular modeling and docking of a PSA-selective substrate (HSSKLQ) to a homology model.
• Virtual positional scanning studies for mechanistic insights into substrate recognition.
• Synthesis and enzymatic assay of novel peptide substrates and aldehyde-containing inhibitors.

Main Results:

• Experimental validation of molecular docking predictions through synthesized peptide substrate hydrolysis rates.
• Successful synthesis and testing of novel transition state analog inhibitors.
• Agreement between docking insights and experimental data for substrate design.

Conclusions:

• The docking methodology is validated for PSA research.
• Molecular modeling is a useful tool for designing substrate-mimetic inhibitors.
• This approach can further elucidate PSA's role in prostate cancer pathobiology.