# IMMUNOCHEMICAL APPROACH TO ACTIN STRUCTURE AND FUNCTION

> **NIH NIH R01** · CINCINNATI CHILDRENS HOSP MED CTR · 1987 · $111,928

## Abstract

Our overall objective is to provide a better understanding of the molecular
mechanisms underlying cellular movements.  Specifically, it is proposed to
extend our understanding of the structure, function and organization of
actin, a major contractile element, using an immunochemical approach.  This
will entail the development of monoclonal and polyclonal antibodies against
specific amino acid sequences found in skeletal muscle actin using
synthetic peptides as immunogens.  The first peptides to be synthesized
will be chosen on the basis of their postulated involvement of certain
amino acid residues in actin functions such as polymerization, myosin
activation, or binding to accessory elements.  The relative hydrophilicity
of the peptide sequence will also be taken into account since this
parameter is a good indicator of antigenicity and surface orientation in
globular proteins.  In later experiments, additional peptides will be
prepared to hydrophilic sequences spaced throughout the actin molecule.
Currently available monoclonal and polyclonal antibodies will also be used
in these studies.

These antibodies will be tested as to their ability to bind to native,
denatured, monomeric and filamentous actin and the spatial relationships of
the peptides in native actin will be assessed by determining the degree of
overlap, if any, in the native molecule.  It is also proposed to analyze
the relationship between each antibody binding site and functional sites in
the actin by determining the effects of these antibodies on actin
polymerization, binding/activation of myosin and its proteolytic fragments,
and binding of accessory proteins.  Conversely, the ability of these
proteins to interfere with antibody binding will be determined.

This immunochemical approach should provide data to support or negate
current hypotheses regarding the three dimensional organization of actin
and should provide new and important information as to those regions of the
molecule that are essential to its many vital functions of this contractile
element.  Moreover, the physiological relevance of this information will be
tested by assaying the effects of the antibodies on living cells.
Ultimately this approach, in combination with crystallographic,
biochemical, and ultrastructural studies, should provide detailed insight
into the molecular mechanisms underlying cell movements in processes such
as division, migration, and contraction.

## Key facts

- **NIH application ID:** 3157618
- **Project number:** 5R01AR036486-02
- **Recipient organization:** CINCINNATI CHILDRENS HOSP MED CTR
- **SAM.gov UEI:** JZD1HLM2ZU83
- **Principal Investigator:** JAMES LESSARD
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $111,928
- **Award type:** 5
- **Project period:** 1986-07-01 → 1989-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157618

## Citation

> US National Institutes of Health, RePORTER application 3157618, IMMUNOCHEMICAL APPROACH TO ACTIN STRUCTURE AND FUNCTION (5R01AR036486-02). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3157618. Licensed CC0.

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