help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chinn, M. K.
Right arrow Articles by Cooke, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chinn, M. K.
Right arrow Articles by Cooke, R.

Biophys J, February 2000, p. 927-939, Vol. 78, No. 2

The Effect of Polyethylene Glycol on the Mechanics and ATPase Activity of Active Muscle Fibers

Marc K. Chinn,* Kathryn H. Myburgh,dagger Truc Pham,* Kathleen Franks-Skiba,* and Roger Cooke*

 *Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, California 94143 USA, and  dagger Department of Physiology, University of Stellenbosch, Stellenbosch 7600, South Africa

We have used polyethylene glycol (PEG) to perturb the actomyosin interaction in active skinned muscle fibers. PEG is known to potentiate protein-protein interactions, including the binding of myosin to actin. The addition of 5% w/v PEG (MW 300 or 4000) to active fibers increased fiber tension and decreased shortening velocity and ATPase activity, all by 25-40%. Variation in [ADP] or [ATP] showed that the addition of PEG had little effect on the dissociation of the cross-bridge at the end of the power stroke. Myosin complexed with ADP and the phosphate analog Vi or AlF4 binds weakly to actin and is an analog of a pre-power-stroke state. PEG substantially enhances binding of these states both in active fibers and in solution. Titration of force with increasing [Pi] showed that PEG increased the free energy available to drive the power stroke by about the same amount as it increased the free energy available from the formation of the actomyosin bond. Thus PEG potentiates the binding of myosin to actin in active fibers, and it provides a method for enhancing populations of some states for structural or mechanical studies, particularly those of the normally weakly bound transient states that precede the power stroke.

Biophys J, February 2000, p. 927-939, Vol. 78, No. 2
© 2000 by the Biophysical Society   0006-3495/00/02/927/13  $2.00


This article has been cited by other articles:


Home page
 J BiochemHome page
M. Kimura and S. Takemori
CH2-Units on (Poly-)ethylene Glycol Radially Dehydrate Cytoplasm of Resting Skinned Skeletal Muscle
J. Biochem., June 1, 2008; 143(6): 841 - 847.
[Abstract] [Full Text] [PDF]

Home page
 J BiochemHome page
M. Kimura and S. Takemori
CH2-Units on (Poly-)ethylene Glycol Radially Dehydrate Cytoplasm of Resting Skinned Skeletal Muscle
J. Biochem., January 1, 2008; 143(1): 123 - 129.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
N. Naber, T. J. Purcell, E. Pate, and R. Cooke
Dynamics of the Nucleotide Pocket of Myosin Measured by Spin-Labeled Nucleotides
Biophys. J., January 1, 2007; 92(1): 172 - 184.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
S. Xu, J. Gu, B. Belknap, H. White, and L. C. Yu
Structural Characterization of the Binding of Myosin{middle dot}ADP{middle dot}Pi to Actin in Permeabilized Rabbit Psoas Muscle
Biophys. J., November 1, 2006; 91(9): 3370 - 3382.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
C. Karatzaferi, M. K. Chinn, and R. Cooke
The Force Exerted by a Muscle Cross-Bridge Depends Directly on the Strength of the Actomyosin Bond
Biophys. J., October 1, 2004; 87(4): 2532 - 2544.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2000 by the Biophysical Society.