A protein-tyrosine kinase has been isolated from a detergent-soluble extract of boar spermatozoa, using poly(Glu, Tyr)4:1 as a substrate. The purification procedure involves sequential column chromatographies on phosphocellulose, polyamino acid affinity and Sephadex G-100 molecular sieving, and results in more than a 1200-fold enrichment. Analysis of the most purified preparation by sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed a major Coomassie blue-stained band of molecular mass 42 kDa. The Tyr-protein kinase does not seem to be autophosphorylable. The Km value for poly(Glu, Tyr)4:1 is relatively low, 2.3 microM, and the tyrosine-polymer phosphorylating activity is apparently inhibited by tyrphostin. The characteristics shown by this new tyrosine kinase--the first to be described in mature male germ cells--support the hypothesis that it belongs to the group of non-receptor-associated tyrosine kinases.
Titolo: | Tyrosine-protein kinase in boar spermatozoa: identification and partial characterization |
Autori: | BERRUTI, GIOVANNA (Primo) |
Parole Chiave: | tyrosine kinase; nonradioactive activity detection; spermatozoa |
Settore Scientifico Disciplinare: | Settore BIO/06 - Anatomia Comparata e Citologia |
Data di pubblicazione: | 9-gen-1992 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | 10.1016/0167-4838(92)90143-2 |
Appare nelle tipologie: | 01 - Articolo su periodico |