Affiliations: University of Belgrade, Institute for the Application
of Nuclear Energy, INEP, Zemun, Serbia | Clinical Center Zemun, Department of Urology, Zemun,
Serbia
Abstract: Prostate specific antigen (PSA) exhibits pronounced heterogeneity in
both primary structure and glycan composition, resulting in the existence of
different molecular forms. Investigation of PSA structure is a demanding task
facing limitations due to inadequate sensitivity of analytical techniques and
low concentrations of the different forms. This study aimed to profile free PSA
(fPSA), especially lower molecular mass species lacking detailed
classification, in normal seminal plasma and in sera from subjects with benign
hyperplasia (BPH) or cancer of the prostate (PCa) as samples of known clinical
relevance. fPSA forms were separated from complex proteomes on chips with
immobilized anti-fPSA antibody followed by detection using surface-enhanced
laser desorption/ionization time of flight mass spectrometry. At least 39
fPSA-immunoreactive species, ranging from 3–29 kDa were detected in seminal
plasma. General fPSA profiles in seminal plasma and sera were similar, but
differed in the abundance and presence of particular peaks/clusters of the
lower molecular mass species. No striking difference in fPSA forms was observed
between BPH and PCa samples, but some distinct peaks varied in intensity and
frequency within or between groups. Obtained data verify fPSA heterogeneity
that might be important for better exploration of all their molecular and
marker potentials.
