Figure 6.

Tyrosine phosphorylation of HK1-sc. Sperm proteins (10 μg) were separated by two-dimensional gel electrophoresis and probed with α-gcs (A), α-HK1 (B), and α-PY (C). An identical pattern of immunoreactivity was seen with all three antisera. Sperm proteins spiked with 0.2 μg of purified rat brain hexokinase were also separated by two-dimensional gel electrophoresis and probed with α-HK1 to confirm the resolving power of the system (D). These results suggested that all HK1-sc was tyrosine phosphorylated, and that the somatic HK1 isoform was not detectable in mature sperm.