General characteristics of the superprecipitation reaction of rat crude uterine myosin B: effects of L-methionine and/or transmethylation blockers on the reaction.
The characteristics of superprecipitation of uterine myosin B from 17 beta-estradiol-3-benzoate-treated rats and the effects of L-methionine and/or 3-deazaadenosine (3-DAA) plus homocysteine thiolactone (HCTL) on the reaction were investigated. The slope and plateau phases of the superprecipitation were dependent on ATP, calcium and magnesium. The calmodulin antagonists, trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide, inhibited the slope and plateau phases, but not the basal superprecipitation. SDS-polyacrylamide gel electrophoresis of the precipitate obtained in complete medium showed the presence of actin and myosin. Addition of 3 mM L-methionine had little affect on either the slope or plateau phases of the basal- or calcium-dependent superprecipitation, while 500 microM 3-DAA plus 1 mM HCTL caused only 9 to 20% decrease in the calcium-dependent superprecipitation in the presence of 0.1 mM or 1 mM ATP. These findings suggest that the calcium-dependent superprecipitation of rat uterine myosin B reflected the contractile response of uterine muscle, and that L-methionine and/or 3-DAA plus HCTL did not affect the calcium-dependent superprecipitation of uterine myosin B.
Ichida
S
S
Department of Biological Chemistry, Faculty of Pharmacy, Kinki University, Higashi-Osaka, Japan.
Ariyoshi
S
S
Tanaka
T
T
Sobue
K
K
Okazaki
Y
Y
Yoshioka
K
K
D000818:Animals; D011232:Chemical Precipitation; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006710:Homocysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D008715:Methionine / Q000494:pharmacology*; D008745:Methylation; D009218:Myosins / Q000302:isolation & purification*; D051381:Rats; D011919:Rats, Inbred Strains; D014372:Tubercidin / Q000494:pharmacology; D014599:Uterus / Q000032:analysis* / Q000187:drug effects
C018258:3-deazaadenosine; D006710:Homocysteine; D008715:Methionine; C007957:homocysteine thiolactone; D009218:Myosins; D014372:Tubercidin