Mechanochemical coupling in flagella. V. Effects of viscosity on movement and ATP-dephosphorylation of Triton-demembranated sea-urchin spermatozoa

Improved techniques have been used to measure movement-coupled ATP-dephosphorylation by suspensions of motile, reactivated sea-urchin spermatozoa. The results confirm that the movement-coupled ATP-dephosphorylation is proportional to beat frequency under conditions where the bend angle remains constant. Some observations suggest that the rate of ATP-dephosphorylation is also related to the amplitude of sliding between flagellar tubules, but our attempts to measure this relationship have been unsuccessful.