# SCANNING CALORIMETRIC STUDIES OF THE MYOSIN ATPASE

> **NIH NIH R01** · SOUTHERN ILLINOIS UNIVERSITY CARBONDALE · 1989 · $55,795

## Abstract

Myosin is responsible for coupling the free energy of ATP
hydrolysis to force production in muscle contraction.  Relatively
little is known about the changes which occur in the myosin
structure during energy transduction, primarily due to a scarcity
of knowledge on the structure of the myosin globular head where the
actin binding site and the ATPase active site reside.

Two recent observations are of interest here:  1.) Spectroscopic
and kinetic techniques demonstrate that the myosin ATPase head
exists in at least two native structural states, in the presence
and absence of nucleotides and actin.  It is not known if
differences between these states are global, if they are confined
to one or more domains, or if they represent movement of domains.
2.) A number of experiments have indicated that the myosin head may
be composed of three domains.  This application proposes to use
differential scanning calorimetry (DSC) to determine the existence
of independent cooperative domains, and to more precisely define
the multistate nature of skeletal myosin heads.  There are three
primary goals of this proposal:  1.) to determine by calorimetry
if the transitions between native myosin states are two-state
transitions, 2.) to determine if the myosin head is more than a
single unit or domain, and 3.) to determine if myosin heads and S-
2 are linked.  The first goal will provide useful information on
the structure of S-1 by indicating whether or not there are two
fundamental, macroscopic, native states for myosin heads.  The
second two goals will provide useful information on the structure
of S-1 and HMM and possible communication between the heads of
myosin, and between each head and S-2.

In order to advance our understanding of the process of energy
transduction in the myosin ATPase, it is important that we define
structural transitions in myosin and the energetics of these
transitions.  In addition we need to ascertain the existence of
cooperative domains, and the coupling of domains within myosin.
This proposal addresses both of these areas.

## Key facts

- **NIH application ID:** 3157977
- **Project number:** 5R01AR037174-03
- **Recipient organization:** SOUTHERN ILLINOIS UNIVERSITY CARBONDALE
- **SAM.gov UEI:** Y28BEBJ4MNU7
- **Principal Investigator:** JOHN W SHRIVER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $55,795
- **Award type:** 5
- **Project period:** 1987-01-01 → 1989-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157977

## Citation

> US National Institutes of Health, RePORTER application 3157977, SCANNING CALORIMETRIC STUDIES OF THE MYOSIN ATPASE (5R01AR037174-03). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3157977. Licensed CC0.

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