# MOLECULAR DYNAMICS OF MUSCLE CONTRACTION

> **NIH NIH R01** · UNIVERSITY OF MINNESOTA · 1992 · $207,269

## Abstract

The long-term goal of this research is to understand the role of
protein rotational motions in the generation of force during muscle
contraction.  Site-selective molecular probes (spin labels or
luminescent dyes) will be attached to myosin or actin, and
spectroscopy experiments (electron paramagnetic resonance (EPR) and
time-resolved optical anisotropy) will provide direct information
about the orientation and rotational motions of he labeled
proteins.  These experiments will be performed on purified
proteins, in which biochemical conditions can be precisely
controlled and monitored, and also on skinned muscle fibers, in
which mechanical performance can be controlled and monitored.
Experimental conditions will be chosen to provide direct tests for
the proposed motions of myosin heads (cross-bridges) and actin
subunits during the generation of force.  The high orientational
resolution of EPR and time resolution of optical anisotropy will
be used to resolve the multiple conformations present under complex
physiological conditions.  Although the primary emphasis will be
on these applications, an integral apart of this project is the
development of the spectroscopic methods.  The five closely related
principal aims of the project are (1) development of EPR techniques
(both conventional and saturation-transfer) (2) application of
these EPR techniques to detect the orientations and rotations of
myosin and actin, (3) development of time-resolved optical
anisotropy techniques (transient absorption, phosphorescence, and
fluorescence), (4) application of these optical techniques to
resolve the rotational motions of myosin and actin, and (5)
correlation of the molecular dynamics with structural, mechanical,
and biochemical measurements on the same preparations.  These
studies should provide direct insight into the role of molecular
dynamics in this fundamental physiological process, and the
technology we are developing should be applicable to a wide range
of other biophysical system in which conformational dynamics are
coupled to enzyme action.

## Key facts

- **NIH application ID:** 3156468
- **Project number:** 5R01AR032961-09
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **SAM.gov UEI:** KABJZBBJ4B54
- **Principal Investigator:** David D Thomas
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $207,269
- **Award type:** 5
- **Project period:** 1983-12-01 → 1993-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3156468

## Citation

> US National Institutes of Health, RePORTER application 3156468, MOLECULAR DYNAMICS OF MUSCLE CONTRACTION (5R01AR032961-09). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3156468. Licensed CC0.

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