Proacrosin conversion inhibitor. Purification and initial characterization of a boar sperm protein which prevents the conversion of proacrosin into acrosin.
J Biol Chem
; 257(6): 3095-9, 1982 Mar 25.
Article
em En
| MEDLINE
| ID: mdl-6801040
ABSTRACT
A proacrosin conversion inhibitor present in boar spermatozoa has been purified and initially characterized. Purification methods included sequential acid extractions of washed spermatozoa at pH 4.0, pH 3.5, and pH 2.5 followed by successive gel filtrations of the pH 2.5 sperm extract supernatant over Sephadex G-75 and G-50. The resulting 8.8-fold purified materials were judged to be homogeneous by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis, had an estimated molecular weight of 12,800, and a constant specific activity of 65 units/mg. Treatment with the proteinases acrosin, trypsin, or chymotrypsin destroyed the highly purified proacrosin conversion inhibitor, indicating that it is a protein. Additional properties of the inhibitor included stability to long periods of storage at pH 3.0 and 4 degrees C, stability to boiling and lyophilization, and an absolute requirement for divalent cations to maintain activity. The highly purified proacrosin conversion inhibitor does not inhibit acrosin. Therefore, it apparently acts to prevent proacrosin conversion by selectively inhibiting the zymogen's self-catalyzed conversion mechanism.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Inibidores de Proteases
/
Espermatozoides
/
Acrosina
/
Proteínas
/
Precursores Enzimáticos
Limite:
Animals
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
1982
Tipo de documento:
Article