Interaction of mouse sperm with purified sperm receptors covalently linked to silica beads

1989 ◽  
Vol 92 (4) ◽  
pp. 713-722
Author(s):  
M.H. Vazquez ◽  
D.M. Phillips ◽  
P.M. Wassarman
Keyword(s):  
Zona Pellucida ◽  
Acrosome Reaction ◽  
Solid Phase ◽  
Galactose Oxidase ◽  
Flow Cytofluorometry ◽  
Mouse Sperm ◽  
Sperm Binding ◽  
Silica Beads ◽  
Covalently Linked ◽  
Solid Phase Assay

We describe a solid-phase assay that has permitted further analysis of zona pellucida glycoprotein, ZP3, as sperm receptor and acrosome reaction-inducer during fertilization in mice. The assay employs silica beads that contain epoxy groups to which purified, mouse oocyte ZP3 is covalently linked (ZP3-beads). ZP3-beads were characterized, e.g. by whole-mount autoradiography and flow cytofluorometry, incubated with capacitated mouse sperm under a variety of conditions, and the extent of sperm binding determined by light microscopy. Results of experiments presented suggest the following: (1) sperm bind specifically to ZP3-beads, but not to silica beads either exposed to 2-aminoethanol or derivatized with oocyte ZP2, fetuin or bovine serum albumin. (2) In nearly all cases, only one sperm binds per ZP3-bead and binding occurs via the sperm head. (3) The extent of sperm binding to ZP3-beads is dependent on ZP3 and sperm concentrations, as well as on incubation time and temperature. (4) Sperm binding to ZP3-beads is unaffected by antibodies directed against ZP3, but is inhibited in a reversible manner by treatment of ZP3-beads with galactose oxidase. (5) Only acrosome-intact sperm bind to ZP3-beads but, once bound, sperm can undergo the acrosome reaction, which results in their release from ZP3-beads. (6) Islet-activating protein and 3-quinuclidinyl benzilate, two inhibitors of the zona pellucida-induced acrosome reaction, prevent sperm bound to ZP3-beads from undergoing the acrosome reaction. These results confirm and extend previous studies of sperm-egg interaction in mice, and suggest that the solid-phase assay will be useful for both cellular and biochemical analyses of mammalian fertilization.

scholarly journals Evidence that aggregation of mouse sperm receptors by ZP3 triggers the acrosome reaction.

1989 ◽  
Vol 108 (6) ◽  
pp. 2163-2168 ◽  
Author(s):  
L Leyton ◽  
P Saling
Keyword(s):  
Acrosome Reaction ◽  
Specific Binding ◽  
Polyclonal Antibodies ◽  
Subsequent Treatment ◽  
Mouse Sperm ◽  
Fab Fragments ◽  
Sperm Binding ◽  
Extracellular Signal ◽  
Acrosomal Exocytosis ◽  
Rabbit Igg

In the mouse, considerable evidence indicates that initial sperm binding to the zona pellucida (ZP) is mediated by ZP3. In addition, this same glycoprotein is also responsible for inducing the acrosome reaction (AR). Whereas the O-linked oligosaccharides of ZP3 appear to mediate sperm-ZP binding, the portion of ZP3 bearing AR activity has not been defined. To try to understand the bifunctional role of ZP3 (binding and AR inducing activities), we have examined the hypothesis that ZP3 aggregates sperm receptor molecules. By analogy with findings in a variety of other extracellular signal transducing systems, including receptors for growth factors and insulin, this aggregation event could initiate the cascade resulting in the AR. To test this hypothesis, we have generated monospecific polyclonal antibodies against ZP2 and against ZP3, and examined the effects of these probes on capacitated sperm incubated in the absence or presence of various ZP protein preparations. For some experiments, we have used proteolytic fragments of ZP3, a preparation known to retain specific binding, but not AR-inducing, activity. We show here that capacitated mouse sperm, incubated with ZP glycopeptides, displayed ARs when incubated subsequently with anti-ZP3 IgG; ARs did not occur when parallel sperm samples were incubated with anti-ZP2 IgG or with anti-ZP3 Fab fragments. When capacitated sperm were treated successively, with (a) ZP3 glycopeptides, (b) anti-ZP3 Fab fragments, and (c) goat anti-rabbit IgG, ARs occurred in the majority of sperm. An alternative approach to examine this hypothesis used ZP proteins obtained from tubal eggs treated previously with bioactive phorbol diester (12-O-tetradecanoyl phorbol-13-acetate [TPA]). This preparation arrests capacitated sperm in an intermediate state of the AR. We demonstrate here that these sperm can be induced to undergo a complete AR by subsequent treatment with anti-ZP3 IgG. Together, these findings are consistent with the hypothesis under examination, and suggest that the aggregation of sperm molecules recognized by ZP3 glycopeptides or by TPA-treated ZP is sufficient to trigger the events that occur during acrosomal exocytosis.

Functional interactions between sulphated polysaccharides and proacrosin: implications in sperm binding and digestion of zona pellucida

Zygote ◽  
1999 ◽  
Vol 7 (2) ◽  
pp. 105-111 ◽  
Author(s):  
R. D. Moreno ◽  
M. Hoshi ◽  
C. Barros
Keyword(s):  
Zona Pellucida ◽  
Active Site ◽  
Acrosome Reaction ◽  
Penetration Rate ◽  
Limited Proteolysis ◽  
Sulphated Polysaccharides ◽  
Functional Interactions ◽  
Sperm Binding ◽  
Sperm Penetration ◽  
Sperm Acrosome Reaction

Acrosin is a serine protease located within mammalian acrosome as inactive proacrosin. Sulphated polymers bind to proacrosin and acrosin, to a domain different from the active site. Upon binding, these polymers induce proacrosin activation and some of them, such as fucoidan, inhibit sperm binding to the zona pellucida. In this work we have studied the interaction of solubilised zona pellucida glycoproteins (ZPGs), heparin and ARIS (Acrosome Reaction Inducing Substance of Starfish) with boar and human acrosin. We have found that ARIS, solubilised ZPGs and fucoidan, but not heparin, inhibit the binding of the monoclonal antibody against human acrosin C5F10 to boar or human proacrosin. These results suggest that fucoidan, solubilised ZPGs and ARIS bind to a related domain on the proacrosin surface. Moreover, ARIS was able to induce human proacrosin activation. On the other hand, neither ARIS nor heparin from porcine intestinal mucosa or bovine lung induced hamster sperm acrosome reaction or sperm motility. Recent data showed that acrosin is involved in dispersal of the acrosomal matrix after acrosome reaction. Thus, the control of the ZPG glycan chains over proacrosin activation may regulate both sperm penetration rate and limited proteolysis of zona pellucida proteins.

scholarly journals Epididymal Maturation and the Acrosome Reaction in Mouse Sperm: Response to Zona Pellucida Develops Coincident with Modification of M42 Antigen1

1988 ◽  
Vol 38 (1) ◽  
pp. 221-233 ◽  
Author(s):  
Katherine A. Lakoski ◽  
Christopher P. Carron ◽  
Christine L. Cabot ◽  
Patricia M. Saling
Keyword(s):  
Zona Pellucida ◽  
Acrosome Reaction ◽  
Mouse Sperm ◽  
Epididymal Maturation

scholarly journals Receptor function of mouse sperm surface galactosyltransferase during fertilization.

1985 ◽  
Vol 101 (4) ◽  
pp. 1501-1510 ◽  
Author(s):  
L C Lopez ◽  
E M Bayna ◽  
D Litoff ◽  
N L Shaper ◽  
J H Shaper ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Dorsal Surface ◽  
Mouse Sperm ◽  
Sperm Surface ◽  
Sperm Binding ◽  
Total Inhibition ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Plasma Membrane Domain ◽  
Dose Dependent

Past studies from this laboratory have suggested that mouse sperm binding to the egg zona pellucida is mediated by a sperm galactosyltransferase (GalTase), which recognizes and binds to terminal N-acetylglucosamine (GlcNAc) residues in the zona pellucida (Shur, B. D., and N. G. Hall, 1982, J. Cell Biol. 95:567-573; 95:574-579). We now present evidence that directly supports this mechanism for gamete binding. GalTase was purified to homogeneity by sequential affinity-chromatography on GlcNAc-agarose and alpha-lactalbumin-agarose columns. The purified enzyme produced a dose-dependent inhibition of sperm binding to the zona pellucida, relative to controls. To inhibit sperm/zona binding, GalTase had to retain its native conformation, since neither heat-inactivated nor Mn++-deficient GalTase inhibited sperm binding. GalTase inhibition of sperm/zona binding was not due to steric blocking of an adjacent sperm receptor on the zona, since GalTase could be released from the zona pellucida by forced galactosylation with UDPGal, and the resulting galactosylated zona was still incapable of binding sperm. In control experiments, when UDPGal was replaced with the inappropriate sugar nucleotide, UDPglucose, sperm binding to the zona pellucida remained normal after the adsorbed GalTase was washed away. The addition of UDPGal produced a dose-dependent inhibition of sperm/zona binding, and also dissociated preformed sperm/zona adhesions by catalyzing the release of the sperm GalTase from its GlcNAc substrate in the zona pellucida. Under identical conditions, UDP-glucose had no effect on sperm binding to the zona pellucida. The ability of UDPGal to dissociate sperm/zona adhesions was both time- and temperature-dependent. UDPGal produced nearly total inhibition of sperm/zona binding when the zonae pellucidae were first galactosylated to reduce the number of GalTase binding sites. Finally, monospecific anti-GalTase IgG and its Fab fragments produced a dose-dependent inhibition of sperm/zona binding and concomitantly blocked sperm GalTase catalytic activity. Preimmune IgG or anti-mouse brain IgG, which also binds to the sperm surface, had no effect. The sperm GalTase was localized by indirect immunofluorescence to a discrete plasma membrane domain on the dorsal surface of the anterior head overlying the intact acrosome. These results, along with earlier studies, show clearly that sperm GalTase serves as a principal gamete receptor during fertilization.

Fluoroimmunoassay of progesterone in human serum or plasma.

1981 ◽  
Vol 27 (7) ◽  
pp. 1176-1179 ◽  
Author(s):  
B L Allman ◽  
F Short ◽  
V H James
Keyword(s):  
Liquid Phase ◽  
Solid Phase ◽  
Clinical Use ◽  
Plasma Samples ◽  
Mixed Anhydride ◽  
Analytical Recovery ◽  
Covalently Linked ◽  
Solid Phase Assay ◽  
Antigen Antibody ◽  
Free Antigen

Abstract We describe a fluoroimmunoassay for progesterone in serum or plasma. The assay involves use of an antiserum to progesterone-11-hemisuccinate and a labeled antigen prepared by linking fluoresceinamine to progesterone-3-carboxymethyloxime by use of a mixed-anhydride procedure. Serum or plasma samples are extracted with hexane. After incubation of a portion of the evaporated extract with antiserum and labeled antigen, antibody-bound and free antigen are separated and the fluorescence of the bound fraction is measured. Separation is effected either by using ammonium sulfate to precipitate liquid-phase antiserum or by using a solid-phase antiserum: antiserum covalently linked to magnetizable cellulose particles, which are separated with a magnet. With either separation technique, analytical recovery, linearity, and precision were acceptable and results compared satisfactorily with those obtained with a conventional radioimmunoassay. The solid-phase assay is more precise and more technically convenient, but the performance of both fluoroimmunoassays was adequate for clinical use in the detection of ovulation.

Interactions between mouse ZP2 glycoprotein and proacrosin; a mechanism for secondary binding of sperm to the zona pellucida during fertilization

2001 ◽  
Vol 114 (22) ◽  
pp. 4127-4136
Author(s):  
Elizabeth Howes ◽  
John C. Pascall ◽  
Wolfgang Engel ◽  
Roy Jones
Keyword(s):  
Zona Pellucida ◽  
Solid Phase ◽  
Binding Assays ◽  
Vitro Fertilization ◽  
Sperm Binding ◽  
Secondary Receptor ◽  
Specificity Of Binding ◽  
Solid Phase Binding ◽  
Complementary Binding

The mouse zona pellucida glycoprotein, mZP2, is thought to be the secondary receptor on eggs for retention of acrosome-reacted sperm during fertilization. Here, we present evidence that one of its complementary binding proteins on sperm is proacrosin/acrosin. mZP2 binds to proacrosin null sperm considerably less effectively than to wild-type sperm. Binding is mediated by a strong ionic interaction between polysulphate groups on mZP2 and basic residues on an internal proacrosin peptide. The stereochemistry of both sulphate groups and basic amino acids determines the specificity of binding. Structurally relevant sulphated polymers and suramin, a polysulphonated anticancer drug, compete with mZP2 for complementary binding sites on proacrosin/acrosin in solid-phase binding assays. The same competitors also displace attached sperm from the zona pellucida of eggs in an in vitro fertilization system. This combination of genetic, biochemical and functional data supports the hypothesis that mZP2-proacrosin interactions are important for retention of acrosome-reacted sperm on the egg surface during fertilization. Safe mimetics of suramin have potential as non-steroidal antifertility agents.

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