# MULTISUBSTRATE ENZYME INHIBITORS

> **NIH NIH R01** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 1987 · $190,248

## Abstract

The long range goals of the project are to develop potent and
specific multisubstrate inhibitors of thymidylate synthase, to use
these as probes to study the active site of the enzyme and to
develop from this information useful new antitumor agents.

Sufficient data on inhibitors of thymidylate synthase (TS) have
been gathered during the current grant period to permit the
construction of one molecule (or a small set) of the currently
studied classes which should have optimal binding and cell
transport properties.  Such molecules will be formed from the
"flexible" or pyrimidine-based folate analogs, substituted at N10
with propargyl and with or without glutamate esterification.  The
nucleotide component will bear methylphosphonate rather than
phosphate at the thymidylate 5'-position, based upon observations
that one such derivative seems to be cytotoxic; i.e., able to
penetrate into cells

A novel approach to the internalization of multisubstrate analogs
will involve replacement of the 5-phosphate with
bromoacetamido.  This type of substitution on thymidine has been
shown by others to give rise to potent, specific, irreversible
inhibitors of thymidylate synthetase.  Such a substitution on
multisubstrate analogs may facilitate cell uptake and provide an
even higher degree of specificity because of the multisubstrate
nature of the inhibitors.

Data currently available suggest that the current generation of
active site probes really represent product-substrate rather than
bisubstrate analogs.  It is expected that introduction of an
electron-withdrawing C=0 or CF2 group at nucleotide C5 in place
of the electron releasing CH2 will permit true mechanism-based
(covalent binding within the TS active site.  Several such
molecules are proposed for synthesis.

Biological data will continue to be gathered by Dr. Y.-C. Cheng,
University of North Carolina.  Inhibitor studies and detailed
kinetic analysis will be performed using purified TS and
dihydrofolate reductase from human sources, and evaluation of
appropriate compounds against human cells in culture will be
conducted.

## Key facts

- **NIH application ID:** 3175379
- **Project number:** 2R01CA037601-04A1
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **SAM.gov UEI:** LL8GLEVH6MG3
- **Principal Investigator:** Arthur D. Broom
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $190,248
- **Award type:** 2
- **Project period:** 1984-03-01 → 1992-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3175379

## Citation

> US National Institutes of Health, RePORTER application 3175379, MULTISUBSTRATE ENZYME INHIBITORS (2R01CA037601-04A1). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3175379. Licensed CC0.

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