NDLI: Osmotic pressure probe of actin-myosin hydration changes during ATP hydrolysis.

Content Provider	PubMed Central
Author	Highsmith, S. Duignan, K. Cooke, R. Cohen, J.
Abstract	Osmotic stress in the 0.5-5 x 10(6) dyne/cm2 range was used to perturb the hydration of actin-myosin-ATP intermediates during steady-state hydrolysis. Polyethylene glycol (PEG) (1000 to 4000 Da), in the 1 to 10 wt% range, which does not cause protein precipitation, did not significantly affect the apparent KM or the Vmax for MgATP hydrolysis by myosin subfragment 1 (S1) alone, nor did it affect the value for the phosphate burst. Consistent with the kinetic data, osmotic stress did not affect nucleotide-induced changes in the fluorescence intensities of S1 tryptophans or of fluorescein attached to Cys-707. The accessibility of the fluorescent ATP analog, epsilon ADP, to acrylamide quenching was also unchanged. These data suggest that none of the steps in the ATP hydrolysis cycle involve substantial hydration changes, which might occur for the opening or closing of the ATP site or of other crevices in the S1 structure. In contrast, KM for the interaction of S1.MgADP.Pi with actin decreased tenfold in this range of osmotic pressure, suggesting that formation of actin.S1.MgADP.Pi involves net dehydration of the proteins. The dehydration volume increases as the size of the PEG is increased, as expected for a surface-excluded osmolyte. The measured dehydration volume for the formation of actin.S1.MgADP.Pi was used to estimate the surface area of the binding interface. This estimate was consistent with the area determined from the atomic structures of actin and myosin, indicating that osmotic stress is a reliable probe of actin.myosin.ATP interactions. The approach developed here should be useful for determining osmotic stress and excluded volume effects in situ, which are much larger than those of typical in vitro conditions.
Related Links	http://dx.doi.org/10.1016/s0006-3495(96)79852-1
Ending Page	2837
Page Count	8
Starting Page	2830
File Format	PDF
ISSN	00063495
e-ISSN	15420086
Journal	Biophysical Journal
Issue Number	6
Volume Number	70
Language	English
Publisher Date	1996-06-01
Access Restriction	Open
Subject Keyword	Biophysics Research in Higher Education
Content Type	Text
Resource Type	Article
Subject	Biophysics

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Conformational changes of the myosin heads during hydrolysis of ATP as analyzed by x-ray solution scattering.

Regulation of actin-activated ATP hydrolysis by arterial myosin.

Theoretical studies of the ATP hydrolysis mechanism of myosin.

Rotational dynamics of spin-labeled F-actin during activation of myosin S1 ATPase using caged ATP.

A physical model of ATP-induced actin-myosin movement in vitro.

ATP induces microsecond rotational motions of myosin heads crosslinked to actin.

Motion of actin filaments in the presence of myosin heads and ATP.

Myosin directionality results from coupling between ATP hydrolysis, lever motion, and actin binding

Role of ATP-Hydrolysis in the Dynamics of a Single Actin Filament

Osmotic pressure probe of actin-myosin hydration changes during ATP hydrolysis.

Similar Documents

Conformational changes of the myosin heads during hydrolysis of ATP as analyzed by x-ray solution scattering.

Regulation of actin-activated ATP hydrolysis by arterial myosin.

Theoretical studies of the ATP hydrolysis mechanism of myosin.

Rotational dynamics of spin-labeled F-actin during activation of myosin S1 ATPase using caged ATP.

A physical model of ATP-induced actin-myosin movement in vitro.

ATP induces microsecond rotational motions of myosin heads crosslinked to actin.

Motion of actin filaments in the presence of myosin heads and ATP.

Myosin directionality results from coupling between ATP hydrolysis, lever motion, and actin binding

Role of ATP-Hydrolysis in the Dynamics of a Single Actin Filament

Osmotic pressure probe of actin-myosin hydration changes during ATP hydrolysis.