# LASER SPECTROSCOPY OF TRIPLET STATES IN PROTEINS

> **NIH NIH R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 1993 · $217,623

## Abstract

Optical spectroscopic techniques have had a major impact on the study of
protein structure and mechanisms.  However, only a small fraction of the
work has employed triplet-state based spectroscopies.  The proposed
research will combine the skills and facilities of a biophysicist (the
principal investigator) and a laser spectroscopist (co-principal
investigator) to develop several laser-based methodologies which will form
the basis of an extensive program to apply the triplet-state
spectroscopies to important problems in molecular biophysics.  A wealth of
significant new information on protein structure and interactions in
solutions is expected from this approach.  The methodologies to be
developed include:  (a) A system from the rapid acquisition (based on a
single excitation pulse) of phosphorescence decay kinetics allowing for
real-time monitoring of structural transitions in proteins as involved in
unfolding and refolding: (b) Use of diffusion-enhanced Forster-type energy
transfer from intrinsic triplet-state donors to study protein structure
and interactions though mapping of the distances of phosphorescent
residues from the surface of the  protein; (c) Time integrated and time
resolved circularly polarized phosphorescence (CCP) to applied in detailed
studies of protein conformations as well as conformational changes that
occur on a time scale comparable to the triplet state lifetime; (d) Laser-
based triplet-triplet absorption to be used to determine triplet state
decay patterns in  systems with low phosphorescence yield.  An extension
of this approach to include time-resolved circular dichroism of triplet-
triplet transitions will provide information complementary to that derived
from CPP.  These approaches will be developed using model enzymes chosen
by virtue of their stability, phosphorescence  properties and structural
information and will be applied to several significant problems in
molecular biophysics.  These include conformational isomerism in enzymes,
structural variability among refolding intermediates, subunit association
in oligomeric enzymes and enzyme-enzyme complex formation patterns.
Another interesting application will be the study of the structural
modifications responsible for the documented differences between enzymes
purified from tissues of  young and old animals.

## Key facts

- **NIH application ID:** 3121662
- **Project number:** 5R01AG009761-04
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **SAM.gov UEI:** GNJ7BBP73WE9
- **Principal Investigator:** ARI GAFNI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $217,623
- **Award type:** 5
- **Project period:** 1990-09-01 → 1995-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3121662

## Citation

> US National Institutes of Health, RePORTER application 3121662, LASER SPECTROSCOPY OF TRIPLET STATES IN PROTEINS (5R01AG009761-04). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3121662. Licensed CC0.

---

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