• Prostate-specific antigen
• fPSA
• Deglicosilazione
• Glicosilazione

Prostate-specific antigen (PSA) is a serine protease enzyme produced primarily by the glandular epithelium of the prostate and secreted into seminal fluid. It is also present in urine and blood. The physiological serum concentration of PSA in men is about 4 ng/ml and tends to increase under pathological conditions. Studies have shown that PSA is also produced by some female tissues subject to hormonal regulation, mainly the breast. The serum concentration of PSA in women is about 1,000 times lower than in men (< 0.004 ng/ml), and recent studies have shown that this value tends to increase in the presence of breast cancer; in this sense, PSA could be an indicator of malignant breast cancer. Immunometric methods available in clinical laboratories to date do not have the sensitivity to quantify the physiological concentration of PSA in women, and consequently it is not possible to measure pathological PSA values possibly related to the presence of breast cancer.
The present thesis work is part of a research project where increased sensitivity of an immunoassay for PSA detection was demonstrated by antibody orientation. This orientation was obtained by reducing the hinge region of immunoglobulin G (IgG) with a mild reducing agent and subsequent binding to appropriately modified surfaces. Therefore, the purpose of this thesis work is to evaluate the baseline values of serum PSA in the female population using the assay developed by the research group. Since the preliminary experiments conducted did not show an increase in sensitivity of the developed assay, possible causes were investigated.
It is known from the literature that the oligosaccharide portion located near the hinge region influences its structure and that the composition of the oligosaccharide chain can vary over time. Therefore, a method was developed to deglycosylate IgG and evaluate how the absence of the oligosaccharide portion affects the reduction of these antibodies. A study will then be conducted to test whether and how deglycosylation affects the binding of IgG to surfaces and whether the increased sensitivity of the developed immunoassay was maintained.