Binding of Arylsulfatase A to Mouse Sperm Inhibits Gamete Interaction and Induces the Acrosome Reaction1

Abstract

We have shown previously that male germ cell-specific sulfoglycolipid, sulfogalactosylglycerolipid (SGG), is involved in sperm-zona pellucida binding, and that SGG and its desulfating enzyme, arylsulfatase A (AS-A), coexist in the same sperm head area. However, AS-A exists at a markedly low level in sperm as compared to SGG (i.e., 1/400 of SGG molar concentration). In the present study, we investigated whether perturbation of this molar ratio would interfere with sperm-egg interaction. We demonstrated that purified AS-A bound to the mouse sperm surface through its high affinity with SGG. When capacitated, Percoll gradient-centrifuged mouse sperm were treated for 1 h with various concentrations of AS-A, their binding to zona-intact eggs was inhibited in a dose-dependent manner and reached the background level with 63 nM AS-A. This inhibition could be partially explained by an increase in premature acrosome reaction. The acrosome-reacted sperm population of the 63 nM AS-A-treated sperm sample was twice that of the control sample (treated with 63 nM ovalbumin) at 1 h (i.e., 32% vs. 15%) and rose to 53% at 2 h. This induction was presumably due to SGG aggregation attributed to AS-A, existing as a dimer at neutral pH, and could be mimicked by anti-SGG immunoglobulin (Ig) G/IgM + secondary IgG antibody. Drastic inhibition (75%) of in vivo fertilization was also observed in females inseminated with sperm suspension containing 630 nM AS-A as compared to the rate in females inseminated with sperm suspension included with 630 nM ovalbumin. Our results demonstrate a promising potential for AS-A as a nonhormonal, vaginal contraceptive.

Investigation of the mechanisms by which the molecular chaperone HSPA2 regulates the expression of sperm surface receptors involved in human sperm-oocyte recognition

“…In addition to well-documented roles in the regulation of myelin sheath deposition in the central nervous system (Eckhardt, 2008), ARSA has also been identified within the acrosome of sperm from a variety of species including boar (Dudkiewicz, 1984;Tanphaichitr et al, 1998), mouse (Tanphaichitr et al, 1990;White et al, 2000;Tantibhedhyangkul et al, 2002;Weerachatyanukul et al, 2003) and human Tantibhedhyangkul et al, 2002). Among its proposed roles in sperm, ARSA has been implicated in the dispersion of the cumulus matrix of cumulus -oocyte complexes (Wu et al, 2007), as well as in the mediation of ZP adhesion Carmona et al, 2002b). Interestingly, these dual roles have also been ascribed to the other predominant component of the sperm complex characterized in this study, SPAM1 (previously known as , and again these roles appear to extend across a large number of species (Primakoff et al, 1985;Cowan et al, 1986;Phelps and Myles, 1987;Gmachl et al, 1993;Cherr et al, 1996;Hunnicutt et al, 1996;Sabeur et al, 1997;Baba et al, 2002).…”

Sperm arylsulfatase A binds to mZP2 and mZP3 glycoproteins in a nonenzymatic manner

“…1) and it had a preferential binding ability to mZP2 and mZP3. Like ASA on the sperm plasma membrane , ASA may be anchored onto the inner acrosomal membrane via its affinity for SGG (Carmona et al 2002b), which also exists on this surface membrane (Supplementary Figure S2, see section on supplementary data given at the end of this article). Our finding on the presence of ASA as an AC component is in agreement with the previous reports in other mammalian sperm (Dudkiewicz 1984, Nikolajczyk & O'Rand 1992, Brandon et al 1997.…”

“…Computational docking shows that SGG/SGC can also fit into a surface cleft consisting of Arg496, a positively charged amino acid, and Ile487, a hydrophobic amino acid (Supplementary Figure S3, see section on supplementary data given at the end of this article). This ASA-SGG interaction is likely a basis on how ASA from the epididymal fluid deposits onto the head convex ridge of transiting sperm without subsequent SGG hydrolysis (Carmona et al 2002b). Likewise, ASA synthesized in spermatogenic cells and targeted to the acrosomal process may remain on the inner acrosomal membrane (Fig.…”

“…The acrosome status of the sperm was determined by Coomassie blue staining (Bleil & Wassarman 1990). Capacitated sperm untreated or treated with ovalbumin or fetuin, which were also subjected to the same electroelution as the ZP glycoproteins, served as negative controls (Carmona et al 2002b), whereas sperm treated with 10 M A23187 were a positive control.…”

Sulfatasen: Struktur, Mechanismus, biologische Aktivität, Inhibition, Anwendung in Synthesen

“…Es wurde auf Spermienoberflächen gefunden und adhäriert vermutlich an sulfatierte OvarienGlycoproteine, sodass es bestimmte Schritte im Befruchtungsprozess steuert. [79][80][81][82] Die humanen lysosomalen Sulfatasen ARSB, GalN6S, GalN3S, GlcN6S, GlcA2S, GlcNS und IdoA2S wurden intensiv untersucht. Sie spielen eine Rolle bei Mucopolysaccharidosen (MPSs), einer Gruppe lysosomaler Speicherkrankheiten, die durch einen gestörten GAG-Katabolismus verursacht werden (Tabelle 3).…”