Identification of 66 kDa phosphoprotein associated with motility initiation of hamster spermatozoa.

Sperm motility is regulated by protein phosphorylation. The 66 kDa protein obtained from hamster sperm flagella was phosphorylated at serine residues associated with the motility initiation. In order to understand the regulatory mechanism of sperm motility, the 66 kDa protein was identified in the present study. The 66 kDa protein was purified by 2-D gel electrophoresis and identified by matrix-assisted laser desorption ionization mass spectrometry, liquid chromatography-tandem mass spectrometry and peptide sequencer. The 66 kDa protein was tubulin β chain. The 66 kDa protein is one of the tubulin β chain isoforms and phosphorylated in relation to the motility initiation. (Reprod Med Biol 2004; : 133-139).