# MOLECULAR DYNAMICS OF MUSCLE CONTRACTION

> **NIH NIH R01** · UNIVERSITY OF MINNESOTA · 1988 · $95,854

## Abstract

Our goal is to understand the role of molecular motions in the generation
of force during muscle contraction, focusing on the proposed rotational
motions of myosin heads (crossbridges) on the thick filament relative to
the actin-containing thin filament.  Direct measurements will be made of
the orientation, rotational motion, and translational motion of spin-labels
and optical probes attached selectively and rigidly to myosin heads, using
spectroscopic instrumentation, theory, and methods that we are developing.
Following preliminary work on purified myosin and myofibrils, the major
emphasis will be on work with glycerinated fibers.  Electron paramagnetic
resonance (EPR) experiments on spin-label attached to the myosin head in
oriented fibers will be performed to study the orientation distribution of
heads in various physiological states (rigor, relaxation, isometric
tension, etc.).  Saturation transfer EPR experiments on the same
preparation will provide information about the time-averaged rotational
motion of the heads.  Using pulsed laser excitation, time-resolved
rotational motions of dyes attached to myosin heads will be detected by
absorption or emission antisotrophy.  Analogous experiments will be
performed on actin motions.  Finally, fluorescence energy transfer from
labeled myosin heads to labeled actin will provide a direct probe of
translational motion of myosin heads relative to actin subunits.  The
results should have a major impact on muscle biophysics, and the
spectroscopic methods developed should have much broader applications.

## Key facts

- **NIH application ID:** 3156465
- **Project number:** 5R01AR032961-05
- **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:** 1988
- **Award amount:** $95,854
- **Award type:** 5
- **Project period:** 1983-12-01 → 1988-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3156465

## Citation

> US National Institutes of Health, RePORTER application 3156465, MOLECULAR DYNAMICS OF MUSCLE CONTRACTION (5R01AR032961-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3156465. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*