# ELLIPSOMETRY STUDIES OF CROSSBRIDGE MECHANISMS IN MUSCLE

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA AT DAVIS · 1988 · $125,781

## Abstract

The studies outline in this proposal are directed towards providing
additional insights into the mechanism of cross-bridge force generation in
muscle cells.  Non-invasive laser diffraction methods, with an emphasis on
the changes of the optical polarization properties upon the interaction of
light with the muscle fiber, is the technique chosen.  The complete
characterization of the optical polarization property known as the
technique of ellipsometry, provides for the determination of both the phase
and the amplitudes of the electric field components after its interaction.
The amplitude information specifically singles out the intrinsically
anisotropic elements of the basic muscle structural unit, the sarcomere.
As such, time evolution studies of the changes in amplitudes monitor the
orientational and intrinsic dynamics of anisotropic elements within the
sarcomere.  Predominently, these are the myosin rods: light meromyosin and
subfragment 2.  Since this region of the sarcomeric structure is undetected
by x-ray diffraction methods and unable to a labelled by extrinsic probes,
the ellipsometry technique provides an important complementary link.  The
phase information provides additional information about the contractile
apparatus.  Here, the phase shift measured in ellipsometry experiments
contains both intrinsic as well as form contributions.  In this proposal,
the method of separation of intrinsic and form information, using
simultaneously obtained amplitude data, is outlined.  This additional
separation of contributing parts gives this method added advantage over the
technique of transmission birefringence, which also contain both
anisotropic and phase information, but is inseparable.  The sequence of
activity outlined in this proposal will focus on: skinned fibers studies;
myosin extracted, subfragment I reconstituted systems; and intact fibers
under isometric tetanus and quick release conditions.

## Key facts

- **NIH application ID:** 3155452
- **Project number:** 5R01AR026817-09
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **SAM.gov UEI:** TX2DAGQPENZ5
- **Principal Investigator:** YIN YEH
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $125,781
- **Award type:** 5
- **Project period:** 1980-04-01 → 1990-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155452

## Citation

> US National Institutes of Health, RePORTER application 3155452, ELLIPSOMETRY STUDIES OF CROSSBRIDGE MECHANISMS IN MUSCLE (5R01AR026817-09). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3155452. Licensed CC0.

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