Proteomic analysis of heparin-binding proteins from human seminal plasma: a step towards identification of molecular markers of male fertility

Abstract

Glycosaminoglycans, especially heparin, are involved in various cell processes such as apoptosis, cell cycle control, platelet activation, capacitation, acrosome reaction and sperm decondensation. Heparin-binding proteins (HBPs) are essential constituents of human seminal fluid, which bind to sperm lipids containing the phosphorylcholine group and mediate the fertilization process. We utilized a proteomic set-up consisting of affinity chromatography, isoelectric focusing (IEF) coupled with matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI TOF/MS) for protein analysis of human HBPs. We resolved 70 different spots on two-dimensional (2-D) gel and subsequently identifi ed these proteins. Forty different types of proteins were identified. Functional analysis revealed that 38% of the proteins belonged to the enzyme category, 20% were involved in RNA processing and transcription, 18% in structure and transport function, and 16% in cell recognition and signal transduction. We also identified 8% of proteins with unknown functions, although their expression in seminal fluid has been documented. Proteins of seminal fluid that bind heparin may be directly involved in sperm capacitation and acrosome reaction (AR), which are the two critical steps for fertilization. This information on HBPs would be useful for identifying potential biomarkers of fertility in the near future.

A multi-faceted approach to understanding male infertility: gene mutations, molecular defects and assisted reproductive techniques (ART)

“…Recent reports have shown that mtDNA point mutations or multiple deletions, mtDNA single nucleotide polymorphisms (SNPs) and mtDNA haplogroups can greatly influence sperm quality and are associated with asthenozoospermia or oligoasthenozoospermia [128][129][130][131][132][133][134][135][136][137][138]. Among the mitochondrial deletions observed, the deletion of 4977 bp was the most prevalent and abundant one.…”

Proteomic approach in the identification of fertility pattern in seminal plasma of fertile men

“…Additional sperm function tests, such as swelling and/or eosine test, do not provide additional information in the assessment of the fertility status (8). Recently, further tests, such as reactive oxygen species determination and chromatin fragmentation, have been proposed for research purposes (9).…”

Proteomics of human seminal plasma: Identification of biomarker candidates for fertility and infertility and the evolution of technology

“…The flight time of each ionized fragment is proportional to the square root of the m/z ratio. As the charge (z) of the ionized proteins is often þ1, the m/z value is often equal to the mass (2003) MALDI-TOF Impaired spermatogenesis Utleg et al (2003) LCMS/MS Prostasome Fung et al (2004) MALDI-TOF; LC-MS/MS Healthy fertile men Pilch and Mann (2006) MALDI-TOF; LTQ-FT Healthy fertile man Yang et al (2007) SELDI-TOF Biomarkers of oligospermia Yamakawa et al (2007) LCMS/MS Infertile versus fertile men Bai et al (2008) SELDI-TOF Severe oligospermia versus healthy fertile men Kumar et al (2008) MALDI-TOF Heparin binding proteins in human seminal plasma Kumar et al (2009) MALDI-TOF Heparin binding proteins in human seminal plasma Wang et al (2009) LCMS/MS Asthenozoospermia Drake et al (2010) LTQ-Orbitrap XL Prostatic secretions Batruch et al (2011) LTQ-Orbitrap XL Post-vasectomy versus healthy fertile men Milardi et al (2012b) LTQ-Orbitrap XL Healthy fertile men Batruch et al (2012) LTQ-Orbitrap XL Non-obstructive azoospermia Kagedan et al (2012) LTQ-Orbitrap XL Prostatitis Molecular Reproduction & Development value. The spectral output produced by MALDI-TOF is represented by a number of protein peaks, which are described by a m/z value on the horizontal axis and by a peak-intensity value on the vertical axis (Schuchardt and Sickmann, 2007).…”