An altered total seminal plasma glycosylation has been associated with male infertility, and the highly abundant seminal plasma glycoprotein prostate-specific antigen (PSA) plays an important role... Show moreAn altered total seminal plasma glycosylation has been associated with male infertility, and the highly abundant seminal plasma glycoprotein prostate-specific antigen (PSA) plays an important role in fertilization. However, the exact role of PSA glycosylation in male fertility is not clear. To understand the involvement of PSA glycosylation in the fertilization process, analytical methods are required to study the glycosylation of PSA from seminal plasma with a high glycoform resolution and in a protein-specific manner. In this study, we developed a novel, high-throughput PSA glycopeptide workflow, based on matrix-assisted laser desorption/ionization-mass spectrometry, allowing the discrimination of sialic acid linkage isomers via the derivatization of glycopeptides. The method was successfully applied on a cohort consisting of seminal plasma from infertile and fertile men (N = 102). Forty-four glycopeptides were quantified in all samples, showing mainly complex-type glycans with high levels of fucosylation and sialylation. In addition, N,N-diacetyllactosamine (LacdiNAc) motives were found as well as hybrid-type and high mannose-type structures. Our method showed a high intra- and interday repeatability and revealed no difference in PSA glycosylation between fertile and infertile men. Next to seminal plasma, the method is also expected to be of use for studying PSA glycopeptides derived from other biofluids and/or in other disease contexts. Show less
In this thesis, methods were developed, and antibody glycosylation was characterized in order to further the clinical application of antibody glycosylation analysis. New mass spectrometric... Show moreIn this thesis, methods were developed, and antibody glycosylation was characterized in order to further the clinical application of antibody glycosylation analysis. New mass spectrometric workflows were introduced in Chapters 2 and 8. Chapter 7 showed the differential characteristics of murine IgG glycosylation of different strains and highlighted the profound differences between humans and mice, with regard to IgG glycosylation. Chapters 4 and 8 showed the use of controlled human situations to study the regulatory mechanisms of IgG and IgA glycosylation. Finally, Chapters 3, 5 and 6, identified glycosidic differences with specified (patho)physiological conditions, which might be exploited for patient stratification in the future. Show less
