Sperm heads, composition

Table IV-1. Composition of sperm heads, sperm nuclei, and nucleoprotamines ...

In 1963, Felix and Hashimoto revised their earlier results on the N-terminals and the amino-acid composition of unfractionated clupeine from Clupea harengus so that there was no longer any essential difference in material from the two herring species. A sample of unfractionated clupeine from North Sea herring sperm heads was prepared again in the late Prof. Felix s laboratory in Frankfurt am Main in March 1963 and sent to Prof. Ando s laboratory in Tokyo for use in structural studies. This sample was found to be not different from unfractionated clupeine from Pacific herring as regards amino-acid composition, N-terminal amino acids (proline, 36% and alanine, 64%), N-terminal sequences (Pro-Arg and Ala Arg-Arg ), and tryptic peptides (Thr.Thr 0.95, Thr Arg 0.84, Val Ser Arg 1.7, Pro Val Arg 0.33, Pro He Arg 0.12, Ala Gly Arg 1.03, Ser Arg 0.52, Ala Ser Arg 0.27, Ala Arg 3.54, Ser-Ser-Ser-Arg-Pro-He-Arg 0.7g, Pro-Arg O.87, Ala Ser Arg Pro-Val-Arg I.O2, Arg 8.16, Arg-Pro-Arg 1.5, Ala-Arg-Arg 0.5, Arg-Arg 10.2 moles/3 moles clupeine) (Nukushina, 1964 Nukushina 1964). 

The biosynthetic development of protamine was first studied by analysis of amino-acid composition and terminal groups of proteins in the nuclei fraction from the testis of rainbowtrout (Salmo irideus) at different stages of spermatogenesis, as shown in Table X-2. These studies showed that in the immature stage DNA is bound to basic proteins of the histone type, which are gradually replaced as maturation proceeds by basic proteins of the protamine type, so that in the fully matured sperm heads DNA is bound only to protamine [Ando and Hashimoto, 1958 (1 2, 3) Felix 1958 Felix, I960]. 

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