# X-RAY DIFFRACTION STUDIES ON MYOSIN SUBFRAGMENT-1

> **NIH NIH R01** · UNIVERSITY OF WISCONSIN-MADISON · 1993 · $245,365

## Abstract

The objective of this research is to improve our understanding of the
molecular basis of muscle contraction by studying the three-dimensional
structure of myosin subfragment-1 by single crystal X-ray diffraction.
Myosin is the major protein in muscle, in which it plays both a structural
and enzymatic role. The myosin rod forms the backbone of the thick
filament whereas the myosin head (subfragment-1, S1) is responsible for
the generation of movement through the hydrolysis of ATP and its
interaction with actin.

During the last funding cycle, the structure of chicken skeletal myosin
subfragment-1 was determined to 2.8 Angstroms resolution and refined to a
nominal R-factor of 22%. This model provides a description of the
secondary and tertiary structure of the molecule and indicates the
location of the active site and actin binding site. These results also
suggest a role for the light chains and a possible mechanism for how
myosin, in conjunction with actin, transduces chemical energy into
mechanical force. The goal of the next funding cycle is to test these
hypotheses by determining the structural transformations that occur on
nucleotide binding and hydrolysis and observing how these effects are
communicated to the actin binding site. This will be accomplished in three
ways.

The first goal will be to complete the structure of chicken skeletal
myosin subfragment-1 and extend the resolution of the data in order to
produce an accurate model that can serve as the basis for interpreting the
genetic, chemical, and kinetic information available for this molecule.

Second, the structures of myosin S1 in the presence of nucleotides will be
determined in an effort to understand the activated state of the molecule.
Concurrent with this, an effort will be made to obtain crystals of the
myosin head in the presence of actin peptides or assembly defective actin
mutants.

Third, the structures of cardiac and scallop myosin subfragment-1 will be
determined to understand the differences in kinetic and functional
behavior of these molecules and the molecular origin of myosin based
regulation.

## Key facts

- **NIH application ID:** 3157086
- **Project number:** 2R01AR035186-09
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **SAM.gov UEI:** LCLSJAGTNZQ7
- **Principal Investigator:** IVAN RAYMENT
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $245,365
- **Award type:** 2
- **Project period:** 1988-08-01 → 1998-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157086

## Citation

> US National Institutes of Health, RePORTER application 3157086, X-RAY DIFFRACTION STUDIES ON MYOSIN SUBFRAGMENT-1 (2R01AR035186-09). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3157086. Licensed CC0.

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