title: A new membrane-associated Ca(2+)-binding protein of rat spermatogenic cells: its purification and characterization.
abstract: A Ca(2+)-binding protein of Mr = 52000, estimated by SDS-PAGE, was purified to a final yield of 0.04% from rat spermatogenic cells. Purification steps included gel filtration, ammonium sulfate precipitation and HPLC. Amino acid analysis showed the content of 34% acidic residues and 15% basic residues. The isoelectric point of this protein was 4.7. Dot-blot analysis indicated that the Ca(2+)-binding protein bound 2 mol of calcium per mol of protein. This protein had two binding sites with dissociation constants of 4.8 microM and 0.2 microM. No appreciable amount of hexose was observed (less than 1 microgram of hexose/70 micrograms of protein). This protein may play an important role such as the Ca(2+)-transport in the plasma membrane of spermatogenic cells.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medicine, Teikyo University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Yamanobe
authors.forename: T
authors.initials: T
authors.lastname: Suyemitsu
authors.forename: M
authors.initials: M
authors.lastname: Komukai
authors.forename: R
authors.initials: R
authors.lastname: Kan
authors.forename: S
authors.initials: S
authors.lastname: Okinaga
authors.forename: K
authors.initials: K
authors.lastname: Arai
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D013087:Spermatids / Q000378:metabolism*; D013090:Spermatocytes / Q000378:metabolism*; D013091:Spermatogenesis
chemical_list: D000596:Amino Acids; D002135:Calcium-Binding Proteins; D002118:Calcium