# SEQUENCE DETERMINANTS OF PROTEIN STRUCTURE & STABILITY

> **NIH NIH R01** · MASSACHUSETTS INSTITUTE OF TECHNOLOGY · 1993 · $261,653

## Abstract

The long term objective of this research is to understand the
relationship between the amino acid sequence of a protein and the ability
of the protein to fold into a stable, three dimensional structure.  This
is important because an understanding of protein stability and folding
underlies any detailed understanding of most biological reactions.
Moreover, much of the promise of biotechnology for improving human health
depends on our eventual ability to manipulate the function of a protein
by altering its sequence.

The studies described here will probe the determinants of protein folding
and stability for two prokaryotic repressor proteins: the P22 Arc protein
and the N-terminal domain of lambda repressor.  These proteins provide
excellent model systems because their three-dimensional structures are
known, the systems are easily manipulated genetically, and biochemical
and biophysical studies of the mutant proteins are straightforward.
Single or multiple mutations that alter hydrophobic packing interactions
or salt-bridge networks in both proteins will be constructed.  The
effects of these mutations on thermodynamic stability will be
investigated by reversible denaturation experiments; changes in the
kinetics of folding and unfolding for Arc variants will be studied by
stop-flow methods.  The conformational properties of the mutants will be
probed by DNA binding activity, the binding of conformation specific
monoclonal antibodies, and in some cases by NMR and/or x-ray
crystallography.  The cooperativity of stabilizing interactions will be
investigated by construction of thermodynamic cycles for sets of singly
and multiply mutant proteins.  Some studies will employ saturation
mutagenesis methods to allow statistical analysis of interactive sequence
information.  Since stability results from the difference between the
free energies of the folded and unfolded protein conformations, the
conformational properties of Arc variants denatured by dilution will also
be determined using circular dichroism, fluorescence, and gel filtration
chromatography.  These studies will provide an important database for
testing and refining our understanding of the sequence determinants of
protein structure and stability and for evaluating algorithms that seek
to predict the effects of sequence changes on protein structure and
function.

## Key facts

- **NIH application ID:** 3126366
- **Project number:** 5R01AI015706-15
- **Recipient organization:** MASSACHUSETTS INSTITUTE OF TECHNOLOGY
- **SAM.gov UEI:** E2NYLCDML6V1
- **Principal Investigator:** Robert T Sauer
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $261,653
- **Award type:** 5
- **Project period:** 1979-05-01 → 1997-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126366

## Citation

> US National Institutes of Health, RePORTER application 3126366, SEQUENCE DETERMINANTS OF PROTEIN STRUCTURE & STABILITY (5R01AI015706-15). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126366. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*