Cryoenzymological Studies on Myosin Subfragment 1

Travers, Franck; Hillaire, D.

doi:10.1111/j.1432-1033.1979.tb13188.x

Cited by 23 publications

(25 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Substitution of up to 50% ethylene glycol for water had little effect on the MgATPase activity (Fig. 3), as already shown (Travers & Hillaire, 1979;Bechet et al, 1979).…”

Section: Effect Of Ethylene Glycol On Ratessupporting

confidence: 74%

“…Comparative studies indicate that their principal effect is due to the hydrophobicity of the solvent acting to restrict the surface area of the protein (Maurel, 1978;Gekko & Timasheff, 1981). Studies of myosin ATPase in the presence of organic solvents such as ethylene glycol were initiated as a preliminary to studying myosin's reactions below 0°C where an antifreeze solvent is required (Travers & Hillaire, 1979;Bechet et al, 1979). Although ethylene glycol was regarded as an inert solvent there was evidence that it changed some of myosin's ATPase properties (Travers & Hillaire, 1979; Barman et al, 1983).…”

mentioning

confidence: 99%

“…Studies of myosin ATPase in the presence of organic solvents such as ethylene glycol were initiated as a preliminary to studying myosin's reactions below 0°C where an antifreeze solvent is required (Travers & Hillaire, 1979;Bechet et al, 1979). Although ethylene glycol was regarded as an inert solvent there was evidence that it changed some of myosin's ATPase properties (Travers & Hillaire, 1979; Barman et al, 1983). Ethylene glycol also affected demembranated muscle fibres: in the absence of nucleotide it reduced the tension held, and in the presence of the unhydrolysed substrate analogue AMPPNP it caused the fibres to relax (Clarke et al, 1980a).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Modification of the interactions of myosin with actin and 5′-adenylyl imidodiphosphate by substitution of ethylene glycol for water

Marston¹,

Tregear²

1984

Biochemical Journal

View full text Add to dashboard Cite

We studied the effect of replacing water by ethylene glycol as solvent on the properties of skeletal muscle myosin, myosin subfragment-1 (S1) and heavy meromyosin. Ethylene glycol (50%, v/v) had no detectable effect on the affinity of myosin or actomyosin for the substrate analogue 5'-adenylyl imidodiphosphate (AMPPNP). However, the rate constants for formation and dissociation of the myosin X MgAMPPNP complex were reduced 200-fold; the logarithm of the dissociation rate was roughly proportional to the fractional concentration of ethylene glycol. Nucleotide dissociation was accelerated at least 300-fold by pure actin but remained slow with regulated actin in the absence of Ca2+. Ethylene glycol substitution reduced the affinity of S1 and the S1 X MgAMPPNP complex for actin equally (100-fold at 50% ethylene glycol). These results show that ethylene glycol has specific effects on myosin's enzymic mechanism, which can account for its effect on the tension and stiffness of glycerinated muscle fibres.

show abstract

“…Substitution of up to 50% ethylene glycol for water had little effect on the MgATPase activity (Fig. 3), as already shown (Travers & Hillaire, 1979;Bechet et al, 1979).…”

Section: Effect Of Ethylene Glycol On Ratessupporting

confidence: 74%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Modification of the interactions of myosin with actin and 5′-adenylyl imidodiphosphate by substitution of ethylene glycol for water

Marston¹,

Tregear²

1984

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…This is because the literature data were obtained with buffers of low ionic strength, which increases the rate of actin activated myosin ATPase. We measured actin activated myosin MgATPase at low ionic strength ([KCl]=0) and found the rate constant 1.54 ± 0.07 mole Pi·(mole myosin head) -1 ·s -1 , in good agreement with published results for actin activated myosin MgATPase at low temperature and in low ionic strength buffer (Travers and Hillaire 1979;White et al 1993).…”

Section: Resultssupporting

confidence: 89%

CaATP prolongs strong actomyosin binding and promotes futile myosin stroke

Gargey

Nesmelova

et al. 2019

Preprint

View full text Add to dashboard Cite

Calcium plays an essential role in muscle contraction, regulating actomyosin interaction by binding troponin of thin filaments. There are several buffers for calcium in muscle, and those buffers play a crucial role in the formation of the transient calcium wave in sarcomere upon muscle activation. One such calcium buffer in muscle is ATP. ATP is a fuel molecule, and the important role of MgATP in muscle is to bind myosin and supply energy for the power stroke. Myosin is not a specific ATPase, and CaATP also supports myosin ATPase activity. The concentration of CaATP in sarcomeres reaches 1% of all ATP available. Since 294 myosin molecules form a thick filament, naïve estimation gives three heads per filament with CaATP bound, instead of MgATP. We found that CaATP dissociates actomyosin slower than MgATP, thus increasing the time of the strong actomyosin binding. The rate of the basal CaATPase is faster than that of MgATPase, myosin readily produces futile stroke with CaATP. When calcium is upregulated, as in malignant hyperthermia, kinetics of myosin and actomyosin interaction with CaATP suggest that myosin CaATPase activity may contribute to observed muscle rigidity and enhanced muscle thermogenesis.

show abstract

“…We slowed down the ATP-binding process by including ethylene glycol in the medium. The effects of this solvent on the steady-state parameters of myosin ATPase (Travers & Hillaire, 1979;Bechet et al, 1979) and of arginine kinase (Travers et al, 1978) and creatine kinase have been studied previously.…”

mentioning

confidence: 99%

Evidence for the two-step binding of ATP to myosin subfragment 1 by the rapid-flow-quench method

Barman¹,

Hillaire²,

Travers³

1983

Biochemical Journal

View full text Add to dashboard Cite

1. The initial steps on the myosin ATPase (EC 3.6.1.3) pathway are taken to be: (formula; see text) A two-step binding for ATP is assumed, but the evidence for it is unconvincing; because of the rapidity of the process unambiguous values for K1 and K2 are not available. 2. We investigated the myosin mechanism by the chemical flow-quench technique. Reaction mixtures containing [gamma-32P]ATP plus myosin subfragment 1 were quenched in unlabelled ATP (ATP chase) or acid (Pi burst). 3. We show that the ATP-chase method can lead directly to unambiguous values for K1 and k+2. 4. The binding process was slowed down by 40% ethylene glycol. It was studied as a function of the ATP concentration. A limiting plateau resulted, showing a two-step binding for ATP, and values for K1 and k+2 were obtained. 5. K1 and k+2 are rather sensitive to the experimental conditions. Ethylene glycol and lowering of the pH decrease both constants, but an increase in KCl concentration increases them. This suggests that the binding of ATP to myosin is of an electrostatic nature. 6. The Pi-burst method can lead directly to k+3 + k-3, but under certain conditions the kinetics are governed by K1 and k+2. This uncertainty of the interpretation of Pi-burst experiments is discussed.

show abstract

Cryoenzymological Studies on Myosin Subfragment 1

Cited by 23 publications

References 31 publications

Modification of the interactions of myosin with actin and 5′-adenylyl imidodiphosphate by substitution of ethylene glycol for water

Modification of the interactions of myosin with actin and 5′-adenylyl imidodiphosphate by substitution of ethylene glycol for water

CaATP prolongs strong actomyosin binding and promotes futile myosin stroke

Evidence for the two-step binding of ATP to myosin subfragment 1 by the rapid-flow-quench method

Contact Info

Product

Resources

About