# ENERGETICS OF CONTRACTION IN SINGLE MUSCLE CELLS

> **NIH NIH R01** · OHIO STATE UNIVERSITY · 1989 · $81,634

## Abstract

Long term objective of this project is to elucidate molecular
sources of observed variations in energetic and mechanical
properties of striated muscle contraction.  Properties to be
investigated include:  rate of energy liberation during an
isometric tetanus and rate of mechanical relaxation.  Experiments
will be performed on fibers isolated with intact membranes from
frog skeletal muscles.  Individual fibers will be studied in order to
take advantage of naturally occurring variation among fibers in
muscles.  Hypotheses and specific aims are:

I.  Isometric energy liberation is a function of composition of the
myosin molecule and concentration of parvalbumin (PV).  Energy
liberation due to cross-bridge cycling at 0 degrees C will be
related to heavy and light chain composition of myosin molecule.
Correlations will be sought between concentration of PV and
magnitude of labile energy liberation.  Myosin and PV isoforms
will be determined by polyacrylamide gel electrophoresis.

II.  Parvalbumin is a soluble relaxing factor.  Time course of
progressive slowing of relaxation and subsequent recovery will be
determined as a function of tetanus duration and temperature
from 0 to 20 degrees C.  Correlations will be sought between
concentration of PV and extent of slowing of relaxation at 0
degrees C.  Using purified frog PV and stopped-flow techniques at
0 to 20 degrees C, rate of dissociation from PV of:  a) Mg2+ will
be compared to time course of slowing of relaxation (and
evolution of labile energy) and b) Ca2+ will be compared to
subsequent recovery of relaxation speed.  Ratio of affinities of
Ca2+ and Mg2+ for PV will be related to amount of labile energy.
Rate of Ca2+ uptake by isolated sarcoplasmic reticulum from 0 to
20 degrees C will be compared to rate of relaxation in prolonged
tetani in fibers.

PV probably exists in all fast contracting skeletal muscles.
Concentration is high in frog, making it useful for study.
Proposed experiments provide stringent tests for the putative role
of PV in muscle function.

## Key facts

- **NIH application ID:** 3155136
- **Project number:** 5R01AR020792-11
- **Recipient organization:** OHIO STATE UNIVERSITY
- **SAM.gov UEI:** DLWBSLWAJWR1
- **Principal Investigator:** JACK A RALL
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $81,634
- **Award type:** 5
- **Project period:** 1978-01-01 → 1991-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155136

## Citation

> US National Institutes of Health, RePORTER application 3155136, ENERGETICS OF CONTRACTION IN SINGLE MUSCLE CELLS (5R01AR020792-11). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3155136. Licensed CC0.

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