title: Purification and characterization of two basic spermatid-specific proteins isolated from the dog-fish Scylliorhinus caniculus.
abstract: In dog-fish spermatid nuclei two intermediate proteins S1 and S2 replace histones before the setting down of protamines. These spermatid-specific proteins were isolated by carboxymethyl-cellulose chromatography and purified by high pressure liquid chromatography. S1 and S2 are characterized by a high content of basic residues and by the lack of cysteine and phenylalanine. The determination of their amino acid composition and of their N- and C-terminal sequences prove that each protein corresponds to a specific molecule which can be considered neither as a histone hydrolytic product nor as a protamines precursor.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000032:analysis; D004284:Dogfish / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D066298:In Vitro Techniques; D008297:Male; D010649:Phenylalanine / Q000032:analysis; D011506:Proteins / Q000302:isolation & purification*; D012754:Sharks / Q000378:metabolism*; D013087:Spermatids / Q000032:analysis*; D013094:Spermatozoa / Q000032:analysis*
chemical_list: D000596:Amino Acids; D011506:Proteins; D010649:Phenylalanine; D003545:Cysteine