Title

Effects of adenylyl imidodiphosphate, a nonhydrolyzable adenosine triphosphate analog, on reactivated and rigor wave sea urchin sperm

UMMS Affiliation

Department of Cell Biology

Date

12-1-1978

Document Type

Article

Subjects

Adenosine Triphosphate; Adenylyl Imidodiphosphate; Animals; Dynein ATPase; Male; Microtubules; Protein Binding; Sea Urchins; Sperm Motility; Spermatozoa

Abstract

A nonhydrolyzable ATP analog, adenylyl imidodiphosphate (AMP-PNP), has been used to study the role of ATP binding in flagellar motility. Sea urchin sperm of Lytechinus pictus were demembranated, reactivated, and locked in "rigor waves" by a modification of the method of Gibbons and Gibbons (11). Rigor wave sperm relaxed within 2 min after addition of 4 micrometer ATP, and reactivated upon addition of 10-12 micrometer ATP. The beat frequency of the reactivated sperm varied with ATP concentration according to Michaelis-Menten kinetics ("Km" = 0.24 mM; "Vmax" = 44 Hz) and was competitively inhibited by AMP-PNP (Ki" approximately to 8.1 mM). Rigor wave sperm were completely relaxed (straightened) within 2 min by AMP-PNP at concentrations of 2-4 mM. The possibilities that relaxation in AMP-PNP was a result of ATP contamination, AMP-PNP hydrolysis, or lowering of the free Mg++ concentration were conclusively ruled out. The results suggest that dynein cross-bridge release is dependent upon ATP binding but not hydrolysis.

Rights and Permissions

Citation: J Cell Biol. 1978 Dec;79(3):827-32.

Related Resources

Link to Article in PubMed

Journal Title

The Journal of cell biology

PubMed ID

153347