Biomaterial Database

Characterization of high-affinity protein D binding sites on the surface of rat epididymal spermatozoa. 1996

J C Hall, and C E Tubbs, and Y Li, and S Ashraf

Department of Biochemistry, North Carolina State University, Raleigh 27695-7622, USA.

125I-labeled protein D was shown to bind to whole rat epididymal sperm in a time-dependent, saturable, and reversible manner. Scatchard analysis indicates that there are 3.4 x 10(5) binding sites/sperm cell with a binding efficiency (Kd) of 2.3 x 10(-10) M. Binding of protein D to sperm reaches equilibrium by 95 min. and is reversible by 30 min. Specific binding of protein D to sperm pre-treated with a dilute trypsin solution is reduced significantly when compared with controls. Our findings establish that protein D-specific binding proteins displaying characteristics of a true receptor are present on the surface of rat epididymal sperm.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D008667	Metalloproteins	Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)	Metalloprotein
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004822	Epididymis	The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D013094	Spermatozoa	Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.	Sperm,Spermatozoon,X-Bearing Sperm,X-Chromosome-Bearing Sperm,Y-Bearing Sperm,Y-Chromosome-Bearing Sperm,Sperm, X-Bearing,Sperm, X-Chromosome-Bearing,Sperm, Y-Bearing,Sperm, Y-Chromosome-Bearing,Sperms, X-Bearing,Sperms, X-Chromosome-Bearing,Sperms, Y-Bearing,Sperms, Y-Chromosome-Bearing,X Bearing Sperm,X Chromosome Bearing Sperm,X-Bearing Sperms,X-Chromosome-Bearing Sperms,Y Bearing Sperm,Y Chromosome Bearing Sperm,Y-Bearing Sperms,Y-Chromosome-Bearing Sperms
D013735	Testicular Hormones	Hormones produced in the testis.	Hormones, Testicular