scholarly journals External mechanical force as an inhibition process in kinesin's motion

2005 ◽  
Vol 390 (1) ◽  
pp. 345-349 ◽  
Author(s):  
Aleix Ciudad ◽  
José María Sancho
Keyword(s):  
Kinetic Theory ◽  
Single Molecule ◽  
Turnover Rate ◽  
Mechanical Force ◽  
Velocity Data ◽  
Atp Turnover ◽  
Force Velocity ◽  
Inhibition Process ◽  
Menten Kinetic ◽  
Inhibition Theory

We analysed published force–velocity data for kinesin using classical Michaelis–Menten kinetic theory and found that the effect of force on the stepping rate of kinesin is analogous to the effect of a mixed inhibitor in classical inhibition theory. We derived an analytical expression for the velocity of kinesin (the stepping rate, equal to the ATP turnover rate) as a function of ATP concentration and force, and showed that it accurately predicts the observed single molecule stepping rate of kinesin under a variety of conditions.

Response of slow and fast muscle to hypothyroidism: maximal shortening velocity and myosin isoforms

1992 ◽  
Vol 263 (1) ◽  
pp. C86-C94 ◽  
Author(s):  
V. J. Caiozzo ◽  
R. E. Herrick ◽  
K. M. Baldwin
Keyword(s):  
Skeletal Muscles ◽  
Relative Content ◽  
Type I ◽  
Myosin Isoforms ◽  
Velocity Data ◽  
Sprague Dawley ◽  
Shortening Velocity ◽  
Sprague Dawley Rats ◽  
Force Velocity ◽  
Fast Twitch

This study examined both the shortening velocity and myosin isoform distribution of slow- (soleus) and fast-twitch (plantaris) skeletal muscles under hypothyroid conditions. Adult female Sprague-Dawley rats were randomly assigned to one of two groups: control (n = 7) or hypothyroid (n = 7). In both muscles, the relative contents of native slow myosin (SM) and type I myosin heavy chain (MHC) increased in response to the hypothyroid treatment. The effects were such that the hypothyroid soleus muscle expressed only the native SM and type I MHC isoforms while repressing native intermediate myosin and type IIA MHC. In the plantaris, the relative content of native SM and type I MHC isoforms increased from 5 to 13% and from 4 to 10% of the total myosin pool, respectively. Maximal shortening velocity of the soleus and plantaris as measured by the slack test decreased by 32 and 19%, respectively, in response to hypothyroidism. In contrast, maximal shortening velocity as estimated by force-velocity data decreased only in the soleus (-19%). No significant change was observed for the plantaris.

Muscle ATP turnover rate during isometric contraction in humans

1986 ◽  
Vol 60 (6) ◽  
pp. 1839-1842 ◽  
Author(s):  
A. Katz ◽  
K. Sahlin ◽  
J. Henriksson
Keyword(s):  
Isometric Contraction ◽  
Turnover Rate ◽  
Knee Extensor ◽  
High Energy ◽  
High Energy Phosphates ◽  
Atp Turnover ◽  
Contraction Duration ◽  
Extensor Muscles ◽  
Before And After ◽  
Fast Twitch

ATP turnover and glycolytic rates during isometric contraction in humans have been investigated. Subjects contracted the knee extensor muscles at two-thirds maximal voluntary force to fatigue (mean +/- SE, 53 +/- 4 s). Biopsies were obtained before and after exercise and analyzed for high-energy phosphates and glycogenolytic-glycolytic intermediates. Total ATP turnover was 190 +/- 7 mmol/kg dry muscle, whereas the average turnover rate was 3.7 +/- 0.2 mmol . kg dry muscle-1 . S-1. The average ATP turnover rate was positively correlated with the percentage of fast-twitch fibers in the postexercise biopsy (r = 0.71; P less than 0.05) and negatively correlated with contraction duration to fatigue (r = -0.88; P less than 0.05). At fatigue, phosphocreatine ranged from 1 to 11 mmol/kg dry muscle (86–99% depletion of value at rest), whereas lactate ranged from 59 to 101. The mean glycolytic rate was 0.83 +/- 0.05 mmol . kg dry muscle-1 . S-1 and was positively correlated with the rate of glucose 6-phosphate accumulation (r = 0.83; P less than 0.05). It is concluded that a major determinant of the ATP turnover rate is the muscle fiber composition, which is probably explained by a higher turnover rate in fast-twitch fibers; fatigue is more closely related to a low phosphocreatine content than to a high lactate content; and the increase in prephosphofructokinase intermediates is important for stimulating glycolysis during contraction.

Optimal Mechanical Force‐Velocity Profile for Sprint Acceleration Performance

2021 ◽  
Author(s):  
Pierre Samozino ◽  
Nicolas Peyrot ◽  
Pascal Edouard ◽  
Ryu Nagahara ◽  
Pedro Jimenez‐Reyes ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Mechanical Force ◽  
Force Velocity

scholarly journals Myosin ATP Turnover Rate: A Mechanism Involved in Thermogenesis in Resting Skeletal Muscle Fibers

2010 ◽  
Vol 98 (3) ◽  
pp. 145a
Author(s):  
Melanie Stewart ◽  
Kathleen Franks-Skiba ◽  
Roger Cooke
Keyword(s):  
Skeletal Muscle ◽  
Turnover Rate ◽  
Muscle Fibers ◽  
Atp Turnover ◽  
Skeletal Muscle Fibers

scholarly journals Single-molecule measurements of the effect of force on Thy-1/αvβ3-integrin interaction using nonpurified proteins

2018 ◽  
Vol 29 (3) ◽  
pp. 326-338 ◽  
Author(s):  
Francesca Burgos-Bravo ◽  
Nataniel L. Figueroa ◽  
Nathalie Casanova-Morales ◽  
Andrew F. G. Quest ◽  
Christian A. M. Wilson ◽  
...  
Keyword(s):  
Protein Purification ◽  
Single Molecule ◽  
Mechanical Force ◽  
Αvβ3 Integrin ◽  
Bimolecular Interactions

Single-molecule measurements combined with a novel mathematical strategy were applied to accurately characterize how bimolecular interactions respond to mechanical force, especially when protein purification is not possible. Specifically, we studied the effect of force on Thy-1/αvβ3 integrin interaction, a mediator of neuron-astrocyte communication.

Alactic ATP Turnover Rate during 30-S Cycle Sprints in Females and Males

1994 ◽  
Vol 87 (s1) ◽  
pp. 125-126 ◽  
Author(s):  
K Bodin ◽  
M Esbjörnsson ◽  
E Jansson
Keyword(s):  
Turnover Rate ◽  
Atp Turnover

scholarly journals The SecA motor generates mechanical force during protein translocation

2020 ◽  
Author(s):  
Riti Gupta ◽  
Dmitri Toptygin ◽  
Christian M. Kaiser
Keyword(s):  
Lipid Bilayers ◽  
Single Molecule ◽  
Protein Translocation ◽  
Mechanical Force ◽  
High Time Resolution ◽  
Unfolded Proteins ◽  
Single Molecule Force Spectroscopy ◽  
Substrate Protein ◽  
Rate Limiting Step ◽  
Substrate Proteins

AbstractThe Sec translocon moves proteins across lipid bilayers in all cells. The Sec channel enables passage of unfolded proteins through the bacterial plasma membrane, driven by the cytosolic ATPase SecA. Whether SecA generates mechanical force to overcome barriers to translocation posed by structured substrate proteins is unknown. Monitoring translocation of a folded substrate protein with tunable stability at high time resolution allowed us to kinetically dissect Secdependent translocation. We find that substrate unfolding constitutes the rate-limiting step during translocation. Using single-molecule force spectroscopy, we have also defined the response of the protein to mechanical force. Relating the kinetic and force measurements revealed that SecA generates at least 10 piconewtons of mechanical force to actively unfold translocating proteins, comparable to cellular unfoldases. Combining biochemical and single-molecule measurements has thus allowed us to define how the SecA motor ensures efficient and robust export of proteins that contain stable structure.

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