IDENTIFICATION OF PHOSPHOSERYL RESIDUES IN PROTAMINES FROM MATURE MAMMALIAN SPERMATOZOAL

Citation
A. Pirhonen et al., IDENTIFICATION OF PHOSPHOSERYL RESIDUES IN PROTAMINES FROM MATURE MAMMALIAN SPERMATOZOAL, Biology of reproduction, 50(5), 1994, pp. 981-986
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Reproductive Biology
Journal title
ISSN journal
0006-3363
Volume
50
Issue
5
Year of publication
1994
Pages
981 - 986
Database
ISI
SICI code
0006-3363(1994)50:5<981:IOPRIP>2.0.ZU;2-T
Abstract
Protamines isolated from ejaculated human, stallion, bull, boar, and r am spermatozoa were subjected to phosphoserine conversion reaction and protein sequencing. Phosphoserines were detected as S-ethylcysteines. Endogenously phosphorylated protamines have previously been found onl y in ejaculated human sperm. In this study, we demonstrate that ejacul ated sperm from other species also contain protamines phosphorylated a t serine residues. In P1-protamines, the endogenously phosphorylated s erines were located at the N-terminal region in all species studied, w hereas in major forms of human and stallion P2-protamines, the serine residues located in the middle region of the molecule were predominant ly phosphorylated. These results support the current DNA binding model in the case of the P1-protamines. The internal location of the phosph orylated serines in the P2-protamines indicates, however, that the bin ding of these proteins to DNA or their interaction with other protamin e molecules may differ from that of P1-protamines. This also suggests that, during sperm maturation, P2-protamines may have a role different from that of P1-protamines.