Purification and characterization of a sperm motility-dynein ATPase inhibitor from boar seminal plasma.
A sperm motility inhibitor from boar seminal plasma was purified. The purification procedure included dialysis against 0.1 M Tris-HCl containing 0.1 mM DTT and chromatographies on SP-Sephadex C-25 and Phenyl-Sepharose CL-4B. With this procedure, the seminal plasma motility inhibitor (SPMI) preparation was highly purified with a 18% recovery of inhibitory activity. The molecular weight of SPMI in native conditions has been estimated at 50,000 by molecular sieving, but 3 polypeptides with molecular weights of 14,000, 16,000 and 18,000 were observed following polyacrylamide gel electrophoresis in denaturing conditions. SPMI is a thermolabile basic protein that is stable between pH 6 and pH 11. The observations that SPMI effects on motility of demembranated spermatozoa are reversed by Mg.ATP and that SPMI inhibited bull dynein ATPase in a concentration-dependent manner suggest that this protein blocks the motility of demembranated spermatozoa by interfering with dynein arm function.
Iwamoto
T
T
Urology Research Laboratory, Royal Victoria Hospital, Montreal, Quebec, Canada.
Tsang
A
A
Luterman
M
M
Dickson
J
J
de Lamirande
E
E
Okuno
M
M
Mohri
H
H
Gagnon
C
C
D000818:Animals; D004398:Dyneins / Q000037:antagonists & inhibitors*; D007526:Isoelectric Point; D008297:Male; D008970:Molecular Weight; D011506:Proteins / Q000302:isolation & purification*; D029607:Seminal Vesicle Secretory Proteins; D013094:Spermatozoa / Q000502:physiology; D013552:Swine
D011506:Proteins; D029607:Seminal Vesicle Secretory Proteins; C424482:seminal vesicle-specific antigen; D004398:Dyneins