Myosin was isolated from 14 different muscles (mammals, lower vertebrates, and invertebrates) of known maximal speed shortening. These myosin preparations were homogeneous in the analytical ultracentrifuge or, a few cases, showed, addition to main peak, part aggregated form. Actin- Ca(++)-activated ATPase activities myosins generally proportional shortening their respective muscles; i.e. greater intrinsic speed, higher activity. This relation found when ranged 0.1 24 muscle lengths/sec. The...

31P nuclear magnetic resonance spectra recorded from intact muophosphate, and the sugar phosphates. Quantitation of these metabolites by was in good agreement with values obtained chemical analyses. The various muscles showed considerable variation their phosphorus profile. Thus, differences could be detected between (a) normal diseased muscle; (b) vertebrates invertebrates; (c) different species same animal. time course change phosphate frog muscle that ATP level remains unchanged until...

1. The characteristics of isometric twitch and tetanic contractions have been determined for normal (N‐EDL, N‐SOL), self‐innervated (S‐EDL, S‐SOL) cross‐innervated (X‐EDL, X‐SOL) extensor digitorum longus (EDL) soleus (SOL) muscles the rat at 35° C. were then used biochemical analyses properties myosin actomyosin. 2. ATPase activities actomyosin X‐EDL decreased to level those N‐SOL or S‐SOL, X‐SOL approached N‐EDL S‐EDL. Of various activities, actin‐ Mg 2+ ‐activated activity showed highest...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhosphorus-31 nuclear magnetic resonance detection of unexpected phosphodiesters in muscleC. Tyler Burt, Thomas Glonek, and Michael BaranyCite this: Biochemistry 1976, 15, 22, 4850–4853Publication Date (Print):November 2, 1976Publication History Published online1 May 2002Published inissue 2 November 1976https://pubs.acs.org/doi/10.1021/bi00667a015https://doi.org/10.1021/bi00667a015research-articleACS PublicationsRequest reuse permissionsArticle...

The myosin light chain of intact arterial smooth muscle displayed a cyclic phosphorylation-dephosphoryla- tion and rephosphorylation in consort with contraction, followed by relaxation, second contraction the muscle.Application pharmacological contractile agonists antagonists vascular revealed that level phosphorylation is related to state muscle.The central role Ca2+ regulation was shown effect ethylene glycol bisw-aminoethyl ether)N,iV,iV',iV'-tetraacetic acid (EGTA) inhibiting inducing...

Tropomyosin, extracted from the leg muscle of frogs that had been injected with [32P]orthophosphate, was fractionated into two components, alpha and beta, on a CM-cellulose column. Radioactivity associated only component. A single phosphorylation site located at serine-283 (pentultimate COOH-terminal end) frog tropomyosin. The same phosphorylated peptide recovered in low yields both rabbit skeletal cardiac presence covalently bound phosphate tropomyosin its absence beta component suggested...

The 20,000-dalton myosin light chain of intact pig carotid arteries was found to be rapidly labeled when the arterial muscle incubated in physiological salt solution at 37 degrees C containing [32P]orthophosphate. Light phosphorylation had a marked requirement for Ca2+ and dependent upon passive tension applied muscle. Norepinephrine- or KCl-induced contractures were associated with concomitant increases phosphorylation.

Phosphorus nuclear magnetic resonance studies of various normal and dystrophic muscles have demonstrated differences in phosphodiester contents. Dystrophic chicken pectoralis muscle contains elevated levels the diester SEP, Duchenne human leg lacks GPC. It is shown that SEP may be characteristic slow fiber types, indicating imcomplete maturation muscle. The activities SEP-metabolizing enzymes been determined microsomes muscle, kidney, intestinal mucosa chickens. There was little difference...

Myosin was prepared from the extensor digitorum longus, gastrocnemius medialis and lateralis, tibialis anterior, flexor of claws anterior limb, diaphragm muscles cat didactyl sloth ( Choloepus hoffmanni Peters). Actin‐activated, Ca 2+ ‐activated, EDTA‐activated ATPase activities myosins were two to four times higher than those same sloth. The difference in ‐activated activity found pH range 5.5 10.0, KCl concentration 50 mM 500 at 7.0. kinetic characteristics indicated that both K m V max...