Surface Proteins of Ejaculated Porcine Sperm and Sperm Incubated in the Uterus

A 70 kDa protein is transferred from the outer acrsomal to the plasma membrane during capacitation

“…Peterson et al [11] have identified three proteins (30, 45 and 70 kDa) in caudal epididymal boar sperm plasma membranes which are not present in caput sperm. Esbenshade and Clegg [43], working with boar sperm, found a 70 kDa plasma membrane protein which increases from 10.1% to 13.5% of the total membrane protein during in utero incubation. Berger [44] found a 78 kDa protein which became exposed on the boar sperm surface during capacitation, the presence of which correlated with increased ability of the cells to fuse with ZP-free hamster ova.…”

Analysis of the surface labelling characteristics of human spermatozoa and the interaction with anti-sperm antibodies

“…The biological functions of the mammalian spermatozoon depend heavily upon the properties of the plasma membrane, which must not only control the passage of ions into the interior of the cell (Bradley & Forrester, 1980;Ashraf et al, 1982;Breitbart & Rubinstein, 1983) but must also interact with constituents of the female genital tract in order to activate those mechanisms responsible for capacitation and the induction of the acrosome reaction (O'Rand, 1977;Ebenshade & Clegg, 1980;Voglmayr et al, 1980). The sperm plasma membrane is also involved in two inde¬ pendent cell recognition events associated with the process of fertilization.…”

Disappearance of the PHA-E Lectin Binding Site on the Surface of Ejaculated Sperm and Sperm Capacitation in the Dog

“…The changes in lectin-binding sites on the sperm surface are thought to be associated with sperm maturation [9,29] and sperm capacitation [7,18]. The ejaculated semen of many species contains decapacitation factors, that cover the sperm surface and inhibit sperm capacitation [6,21], and some of the specific glycoproteins secreted by the accessory glands act as decapacitation factors [28]. The presence of PHA-E lectin-binding glycoprotein on the surface of the entire head and mid-piece of canine ejaculated sperm, but not on epid- idymal sperm, was demonstrated in this study.…”

“…The results of the present study indicate that a PHA-E lectin-binding protein which is thought to be secreted by the canine prostate is one of the decapacitation factors for canine sperm and that loss of the PHA-E-binding protein on the surface of canine sperm in the oviducts causes induction of sperm capacitation by certain substances, e.g., glycosaminoglycans, in the oviductal fluid of the estrous bitch. It has been found that the glycoproteins on the surface of sperm are removed after exposure to fluids of the female reproductive tract of estrous animals and that their removal induces sperm capacitation [5,6,21,31]. Proteases (enzymes that hydrolyze proteins) in the fluids of the uterus and oviduct have been reported to hydrolyze sperm surface glycoproteins [5,19], and it will be necessary to examine the reproductive tract fluid of estrous bitches for the presence of proteases.…”

“…It is known that the glycoproteins produced by the prostates and seminal vesicles are contained in the semen [2,5,24] and that some of them act as decapacitation factors [2,24]. The decapacitation factors on the surface of the sperm are lost as a result of the action of proteolytic enzymes in the uterus and oviduct [5,6,19], and sperm capacitation is then promoted by some components of oviductal fluid, e.g., glycosaminoglycans [11,15,22]. Sperm capacitation is induced by an influx of Ca into the cytoplasm of the sperm [23,25,27].…”