Epididymal sperm were collected and incubated under noncapacitating (NC) and capacitation (CAP) conditions in the presence and absence of KH7. Proteins were solubilized, separated by gel electrophoresis, and assayed for the presence of protein tyrosine phosphorylation by immunoblotting with the anti-phosphotyrosine antibody.
(A) Sperm coincubated with various concentrations of KH7. The band at Mr ~116,000 (arrow) is hexokinase, which is constitutively tyrosine phosphorylated.
(B) In the presence of 10 μM KH7 and 1 mM dbcAMP, the prototypical protein tyrosine phosphorylation pattern was observed.