Identification of prostate-specific antigen (PSA) isoforms in complex biological samples utilizing complementary...

Area of Science:

• Biochemistry
• Proteomics
• Molecular Biology

Background:

• Prostate-specific antigen (PSA) blood levels are crucial for diagnosing and monitoring prostate diseases.
• Identifying distinct PSA molecular forms could significantly improve the conventional PSA test's clinical utility.
• Understanding PSA structural variants may enhance discrimination of prostate disease pathologies and stages.

Purpose of the Study:

• To comprehensively identify prostate-specific antigen (PSA) variants present in seminal fluid.
• To establish a multi-step analytical protocol combining gel-based methods and mass spectrometry for variant identification.
• To demonstrate the proof-of-principle for this approach in complex biological samples.

Main Methods:

• Development of a multi-step protocol involving gel electrophoresis (SDS-PAGE, zymography) and Western blotting.
• Mass spectrometric identification using MALDI-Orbitrap analysis of excised and digested gel bands.
• Utilizing MASCOT and SEQUEST search engines for sequence annotation and PSA variant identification.

Main Results:

• Successful identification of multiple prostate-specific antigen (PSA) variants in seminal fluid.
• Demonstration of distinct molecular characteristics of identified PSA forms.
• Validation of gel-based annotations through mass spectrometry and enzymatic activity monitoring.

Conclusions:

• The developed multi-step analytical approach is effective for identifying multiple PSA variants in complex biological samples.
• This method provides high accuracy and distinct molecular characterization of PSA forms.
• Further application of this protocol can advance the understanding and clinical management of prostate diseases.