# Development of a Laser-Assisted NMR Technology for the Atomic-Resolution Analysis of Medically Relevant Biomolecules in Solution at Submicromolar Concentration

> **NIH NIH R01** · UNIVERSITY OF WISCONSIN-MADISON · 2020 · $333,753

## Abstract

Project Summary
The goal of this application is to develop a novel laser-enhanced NMR technology for the highly sensitive
atomic-resolution analysis of amino acids, polypeptides and proteins in solution, down to sub-micromolar
concentration. The instrumentation involved in this work comprises high-power lasers (both continuous-wave
and pulsed) coupled, via fiber optic, to a commercial 600 MHz NMR spectrometer equipped with a quadruple-
resonance (HFCN) cryogenic probe. Transient electronic absorption measurements will also be performed to
monitor the photoexcited triplet lifetime of photo-CIDNP dyes. The advances gained via this research will
enable the high-resolution NMR analysis of polypeptides and proteins at unprecedentedly low concentration.
The proposal further extends key method-development originally carried out in the PI’s laboratory on single
amino acids to the realm of polypeptides and proteins. We will accomplish the above goals within three steps.
First (Specific Aim #1), photo-CIDNP will be explored in the presence of a newly acquired cryogenic probe at
600 MHz, to further extend NMR sensitivity in solution to the nanomolar range. Our studies will employ the
recently developed photosensitizer fluorescein, tailored to low-concentration photo-CIDNP, and will take
advantage of thorough oxygen depletion in NMR samples, and will employ ultrafast femtosecond laser
irradiation for laser-driven NMR sensitivity enhancement. Second (Specific Aim #2), we will systematically
extend photo-CIDNP in solution, by extending its applicability to polypeptides, and proteins in simple buffered
solution and in more complex highly crowded physiologically relevant environments. We will accomplish the
above goal by testing new photosensitizer dyes tailored to optimal performance in the presence of proteins, by
developing appropriate multidimensional photo-CIDNP NMR pulse sequences, and by collecting data in
buffered solution, cell-free systems, and possibly live bacterial cells. Third (Specific Aim #3), we will extend
photo-CIDNP to non-aromatic amino acids by implement NOE modules within photo-CIDNP pulse sequences
to spread the photo-CIDNP-enhanced magnetization of polypeptides and proteins from aromatic residues to
other amino acids. Finally, we will pioneer new double-laser-irradiation experiments for the transient oxidation
of the carbonyl functional group of proteins, which is present in all amino acids, and is known to be particularly
oxidizing in its photo-excited state. Once the proposed new technology has been developed, it will immediately
become possible to collect hyperpolarized NMR data in solution on amino acids, polypeptides and proteins of
biomedical relevance at sub-micromolar concentration in solution and cell-like environments.

## Key facts

- **NIH application ID:** 10020189
- **Project number:** 5R01GM125995-03
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** Silvia Cavagnero
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $333,753
- **Award type:** 5
- **Project period:** 2018-09-08 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10020189

## Citation

> US National Institutes of Health, RePORTER application 10020189, Development of a Laser-Assisted NMR Technology for the Atomic-Resolution Analysis of Medically Relevant Biomolecules in Solution at Submicromolar Concentration (5R01GM125995-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10020189. Licensed CC0.

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