Journal ArticleDOI
Solubilization and partial purification from mouse sperm membranes of the specific binding activity for 3-quinuclidinyl benzilate, a potent inhibitor of the zona pellucida-induced acrosome reaction.
Reads0
Chats0
TLDR
This study describes the solubilization and partial purification of the mouse sperm QNB binding activity which may represent a component of the putative receptor complex for ZP on the sperm plasma membrane and proposes that these proteins, including G(i), may act as part of a sperm receptors complex for the ZP.Abstract:
3-Quinuclidinyl benzilate (QNB), a potent antagonist of muscarinic acetylcholine receptors, has been demonstrated to inhibit specifically the zona pellucida (ZP)-inducud acrosome reaction (AR) in mouse sperm (Florman and Storey, 1982; Dev Biol 91:121–130). In this study we describe the solubilization and partial purification of the mouse sperm QNB binding activity which may represent a component of the putative receptor complex for ZP on the sperm plasma membrane. Sperm membranes were isolated from cell homogenates of washed, capacitated, epididymal mouse sperm. Scatchard plots of QNB binding to these membranes indicated a single class of binding sites with KD = 7.2 nM and Bmax = 8700 sites/cell. These binding characteristics are similar to those seen with QNB binding to whole cells (Florman and Storey, 1982, J Androl 3:157–164). Sperm membranes were solubilized using 1% digitonin/0.2% cholate, and the resultant detergent-soluble fraction possessed QNB binding activity similar to that of intact membranes. The detergent-soluble fraction maintained intact ZP receptor(s)–G protein coupling in that treatment of this fraction with either ZP or mastoparan resulted in a 35% or 65% increase in specific GTPγS binding, respectively. The solubilized membrane preparation was fractionated by gel permeation HPLC. A majority of specific QNB binding activity was confined to one HPLC fraction. Analysis of this fraction by SDS–PAGE revealed a complex of approximately 5 proteins unique to this fraction. The most prominent protein had a Mr of 72 kDa, which is within the Mr range for muscarinic receptors. A protein with Mr = 41 kDa was also present within this fraction. Subsequent pertussis toxin (PTX)-catalyzed ADP-ribosylation of this fraction revealed this protein to be the α subunit of the Gi class of G proteins. Although the QNB binding activity could not be positively identified, we propose that it is contained in one or more of the proteins unique to this fraction and that these proteins, including Gi, may act as part of a sperm receptor complex for the ZP. © 1994 Wiley-Liss, Inc.read more
Citations
More filters
Journal ArticleDOI
The Biological and Functional Significance of the Sperm Acrosome and Acrosomal Enzymes in Mammalian Fertilization
TL;DR: This review focuses on the formation and contents of the sperm acrosome as well as the mechanisms underlying the induction of the acrosomes reaction.
Journal ArticleDOI
Regulating the acrosome reaction
TL;DR: The mechanism by which ZP3 generates Ca2+ entry, as well as the upstream events leading to this influx and downstream processes that couple it with exocytosis are discussed.
Journal ArticleDOI
Ligand-binding characterization of xanthophyll carotenoids to solubilized membrane proteins derived from human retina
TL;DR: This investigation provides the first direct evidence for the existence of specific xanthophyll-binding protein(s) in the vertebrate retina and macula.
Journal ArticleDOI
Calcium influx into mouse spermatozoa activated by solubilized mouse zona pellucida, monitored with the calcium fluorescent indicator, fluo-3. inhibition of the influx by three inhibitors of the zona pellucida induced acrosome reaction: Tyrphostin A48, pertussis toxin, and 3-quinuclidinyl benzilate
TL;DR: Results indicate that [Ca2+]i increase in is an early, if not the initial, reaction in the sequence leading to zona pellucida induced acrosomal exocytosis in mouse sperm.
Journal ArticleDOI
The sperm, a neuron with a tail: ‘neuronal’ receptors in mammalian sperm
TL;DR: A number of plasma membrane receptor types originally thought to be specific to neurons have been found in other somatic cells, and the mammalian sperm and neuron appear to share many of these‘neuronal’receptors.
References
More filters
Journal ArticleDOI
Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4
TL;DR: Using an improved method of gel electrophoresis, many hitherto unknown proteins have been found in bacteriophage T4 and some of these have been identified with specific gene products.
Journal Article
Cleavage of structural proteins during the assemble of the head of bacterio-phage T4
TL;DR: Using an improved method of gel electrophoresis, many hitherto unknown proteins have been found in bacteriophage T4 and some of these have been identified with specific gene products as mentioned in this paper.
Journal ArticleDOI
The Attractions of Proteins for Small Molecules and Ions
TL;DR: The number and variety of known compounrjs between proteins and small molecules are increasing rapidly and make a fascinating story as discussed by the authors, and there are many compounds of serum albumin, which was used during the war by many chemists, most of whom found at least one 6ew compound.
Journal ArticleDOI
Identification of a family of muscarinic acetylcholine receptor genes
TL;DR: Analysis of human and rat genomic clones indicates that there are at least four functional muscarinic receptor genes and that these genes lack introns in the coding sequence.
Journal ArticleDOI
Muscarinic Receptor Subtypes
TL;DR: The aim of this review is to discuss the structure, function, and binding properties of the different muscarinic receptor species, attempting where possible to coordinate the diverse experimental data into a uniform picture.