Identification of asthenozoospermia-associated proteins in human seminal plasma by shotgun proteomic strategy / 中华男科学杂志

<p><b>OBJECTIVE</b>To identify asthenozoospermia-associated proteins in seminal plasma by the shotgun proteomic strategy.</p><p><b>METHODS</b>Six seminal plasma samples were collected by Percoll respectively from healthy fertile and asthenozoospermia volunteers, balanced, mixed, and then the mixture was separated by SDS-PAGE. The proteins in the gel were enzymolyzed, extracted and identified by the shotgun proteomic strategy. The identified proteins with the unique peptide count > or =2 or the unique peptide count=1 but the total count > or =4 were compared between the two groups.</p><p><b>RESULTS</b>A total of 172 differential proteins were identified, of which, 89 were exclusively from the asthenozoospermia and 83 exclusively from the healthy fertile men. According to the molecular function, these differential proteins were mainly the types of signal transduction and catalytic activity.</p><p><b>CONCLUSION</b>Functionally, 10 of the proteins are particularly important, which include annexin VI isoform 2, isoform 1 of interleukin-6 receptor subunit beta precursor, Mr 400,000 protein, cytosolic dynein heavy chain, alpha-actinin-4, receptor-type tyrosine-protein phosphatase eta precursor, vitamin D-binding protein precursor, protein S100-A11, protein S100-A9 and ANXA4.</p>

Identification of differential proteins in the seminal plasma of healthy fertile and non-obstructive azoospermia men by shotgun proteomic strategy / 中华男科学杂志

<p><b>OBJECTIVE</b>To identify differential proteins in the seminal plasma of healthy fertile men and non-obstructive azoospermia patients by the shotgun proteomic strategy.</p><p><b>METHODS</b>Six seminal plasma samples from 3 healthy fertile and 3 non-obstructive azoospermia volunteers were collected by Percoll isolation, balanced-mixed, and followed by separation of the mixture by SDS-PAGE. The proteins were subjected to in-gel enzymolysis and isolation of peptide fragments, and then identified by the shotgun proteomic strategy. Then comparative analyses were made between the two groups on the identified proteins with the unique peptide count > or = 2 and = 1 but with the peptide count > or = 4.</p><p><b>RESULTS</b>A total of 213 differential proteins were identified, 133 in the non-obstructive azoospermia patients and 80 in the healthy fertile men. According to the molecular function, these differential proteins mainly fell into the types of signal transduction, cytoskeleton and catalytic activity, especially oxidoreductase activity in the latter type. Eighteen of the differential proteins were found to be of particular significance, including dynein heavy chain, fatty acid synthase, and tubulin alpha-6 chain.</p><p><b>CONCLUSION</b>The differential proteins identified in this study were many in number and various in function, which not only demonstrated the value of the shotgun proteomic strategy in protein identification, but also suggested the complicated pathogenesis and varied types of non-obstructive azoospermia. The samples must be selected strictly based on their gene and histological types. Non-obstructive azoospermia was shown to be related with the M phase of the mitotic cell cycle at the protein level, but its specific mechanism remains unknown.</p>

Identification of proteins in the seminal plasma of healthy fertile men by shotgun proteomic strategy / 中华男科学杂志

<p><b>OBJECTIVE</b>To identify proteins in the seminal plasma of healthy fertile men.</p><p><b>METHODS</b>Three seminal plasma samples were collected from healthy fertile volunteers by Percoll isolation, and then the balanced mixture of the seminal plasma was separated by SDS-PAGE. The proteins in the gel band underwent enzymoloysis, and was extracted and identified by shotgun proteomic strategy.</p><p><b>RESULTS</b>A total of 331 proteins were identified, with the molecular weight (MW) ranging from 8 000 to 572 068 and the isoelectric point (pI) from 4.36 to 11.05. Based on the molecular function and biological process of the proteins, 51 (15.4%) were classified as transport proteins, 11 (3.32%) as cell movement proteins, 63 (19.03%) as signal transduction proteins, 147 (44.4%) as proteases, 38 (11.5%) as enzyme regulator proteins, 21 (6.3%) as programmed cell death proteins, 12 (3.62%) as structural proteins and 59 (17.8%) as proteins with unknown molecular function.</p><p><b>CONCLUSION</b>Shotgun proteomic strategy is a good method for protein identification. Annexin A, Annexin-associated proteins and the Ras-related protein Rab were the major members of the signal transducer proteins identified. Ca2+ and G protein signal pathways may play a most important role in the extracellular signal transduction into cells, but the interactions between these proteins remain unknown. The great quantity of enzymes and enzyme regulator proteins identified in the seminal plasma may be closely related with the maintenance of sperm motility and metabolism.</p>