Human Seminal Plasma Proteins Research Articles

Proteins of human semen. I. Two-dimensional mapping of human seminal fluid.

The proteins in human seminal plasma were mapped by high-resolution two-dimensional electrophoresis (ISO-DALT and BASO-DALT systems). When analyzed under dissociating conditions, samples from normal fertile males revealed a pattern of over 200 proteins, ranging in mass from 10 000 to 100 000 daltons. Comparison of the mapped proteins from these males and those who had undergone vasectomy allowed us to identify one series of glycoproteins as missing from the semen from vasectomized individuals. Glycoproteins isolated by affinity chromatography with use of concanavalin A were also mapped. Some of the protein spots were identified either by co-electrophoresis with purified proteins or by the electrophoretic transfer of proteins to nitrocellulose sheets and subsequent detection by immunological procedures. The proteins identified include a number of serum proteins as well as prostatic acid phosphatase and creatine kinase. Proteolytic events shown to occur during the liquefaction of semen that occurs early after collection indicate the importance of carefully controlled collection and preparation methods for clinical evaluation of seminal plasma. Ethylenediaminetetraacetic acid and phenylmethylsulfonyl fluoride inhibit this proteolysis.

Preliminary characterization of a new androgen-binding protein in human seminal plasma.

In order to obtain comparative analysis between the steroid binding proteins from blood serum and seminal plasma, fresh samples were incubated and assayed in parallel with the following tritiated steroids: dihydrotestosterone, testosterone, cortisol, progesterone and estradiol. Thereafter, and using techniques such as (1) polyacrilamide disk gel electrophoresis with elution of proteins from the gel slices, (2) ammonium sulphate precipitation, (3) enzymatic hydrolysis, and (4) gel filtration on Sephadex G-100, there was a resemblance in the electrophoretic patterns confirming the presence in both fluids of proteins like TeBG, CBG, and Albumin, previously described in blood serum. In seminal fluid, but not in blood serum, another small protein with androgen binding capacity was found and its preliminary characterization demonstrated: disappearance with enzymatic treatment, low molecular weight, negative charge, and precipitation range with ammonium sulphate from 30 to 35%. Its elution profile on Sephadex G-100 was contaminated with albumin.

Studies on the proteins of human seminal plasma: I. Characterisation of two esterase systems

Two esterases were demonstrated to be present in seminal plasma. The enzymes were differentiated in terms of electrophoretic mobility, immunogenicity and sensitivity to organophosphorus esters. According to their respective mobilities in the α and βγ zone they were called α-esterase and βγ-esterase. Gel filtration also separated the two esterases. The βγ-enzyme showed marked heterogeneity in starch-gel electrophoresis. It was eluted in a single peak from Sephadex G-200. Its molecular weight was estimated to be 69 000-77 000. The α-esterase, which was not detectable in all seminal plasma samples, was shown to form a complex with the iron-binding protein lactoferrin.

The Effect of Temperature on the Proteins of Human Seminal Plasma during Storage

The Effect of Temperature on the Proteins of Human Seminal Plasma during Storage

Immunoelectrophoretic studies on glycoproteins of the human seminal plasma.

The effect of neuraminidase on glycoproteins with endstanding N-acetylneuraminyl groups results in a significant decrease of their electrophoretic mobilities. This phenomenon was used for the identification of glycoproteins present in the human seminal plasma. Immunoelectrophoretic analyses before and after treatment with neuraminidase revealed that several protein constituents including various enzymes are glycoproteins with terminal N-acetylneuraminyl groups, most of which are secreted by the prostate gland. Not all types of glycoproteins can be detected by the methods employed. There is reason to believe that some of the glycoproteins originating in the seminal vesicles do not react with precipitating antisera specifically directed against human seminal plasma proteins.

Analysis of the proteins in human seminal plasma

The proteins in human seminal plasma were analyzed by cellulose acetate electrophoresis, immunoelectrophoresis, and disc electrophoresis gel diffusion. Cellulose acetate electrophoresis resulted in four bands, while disc electrophoresis produced fifteen which were compared to those formed with serum. Specific identification was made by immunoelectrophoresis and disc electrophoresis gel diffusion with antisera against human serum and twelve individual proteins. Human seminal plasma was shown to contain six proteins, three of which were identified by reactions with specific antisera as albumin, transferrin and immunoglobulin G, and three by their location as a prealbumin an alpha 1 globulin and an alpha 2 globulin.