# KINETICS OF THE MUSCLE CONTRACTILE APPARATUS

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 1987 · $189,881

## Abstract

The goal of this research program is to relate the biochemical and
mechanical states of the mechanism of muscle contraction by studying the
detailed mechanical properties of muscle preparations in which the
concentration of relevant chemical species is subject to experimental
variation.  Force transients, which occur after the length or load on a
muscle is rapidly altered and are related to molecular events of the
cross-bridge cycle, will be measured in conditions of reduced myofibrillar
concentration of the reaction substrate (ATP), at increased concentration
of the reaction products (ADP and Pi) and at aletered pH.  These conditions
can be imposed on "skinned" single muscle fiber preparations which have had
their surface membrane removed.  The effects of altered chemical
environment on the transient events will be related to the known kinetics
of actomyosin in solution to determine how organization of the filament
lattice influences rates of intermediate reactions and how free energy
change of the chemical reaction is coupled into force generation.  The
influence of the lateral spacing between the filaments on the mechanical
compliance and reaction rates of the cross-bridge will be determined in
skinned and intact muscle fibers.  A new white light diffraction method,
using acousto-optic deflection, will be used to control sarcomere length at
the high spacial and time resolution necessary to perform the transient
experiment in skinned muscle fibers.  A new method of rapid activation of
the fibers will be used to improve the uniformity and reproducibility of
the contractions.  This will involve flash photolysis of a photolabile
compound, termed caged ATP, in the interior of rigor muscle fibers in the
presence of calcium.  The pulse of light will release ATP and initiate the
contraction.  The significance of these studies extends over a broad range
of muscle physiology and cell motility.

## Key facts

- **NIH application ID:** 3155463
- **Project number:** 2R01AR026846-08
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **SAM.gov UEI:** GM1XX56LEP58
- **Principal Investigator:** YALE E GOLDMAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $189,881
- **Award type:** 2
- **Project period:** 1980-04-01 → 1992-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155463

## Citation

> US National Institutes of Health, RePORTER application 3155463, KINETICS OF THE MUSCLE CONTRACTILE APPARATUS (2R01AR026846-08). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3155463. Licensed CC0.

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