# STUDIES ON DIPHTHERIA TOXIN AND ITS RECEPTOR

> **NIH NIH R01** · UT SOUTHWESTERN MEDICAL CENTER · 1990 · $162,183

## Abstract

The overall objective of this grant proposal is to characterize the
receptor binding domain(s) of diphtheria toxin, and to
characterize fully and purify the specific diphtheria toxin-binding
cell surface protein(s) from highly toxin-sensitive Vero cells.

The diphtheria toxin-binding proteins are detected by i) prebinding
toxin to extrinsically radiolabeled Vero cells, followed by non-
ionic detergent lysis and immunoprecipitation of the formed
(receptor-toxin) complexes with anti-toxin coupled to Sepharose,
and by ii) chemical cross-linking of radioiodinated diphtheria toxin
bound to its receptor on the surface of Vero cells.  Monoclonal
antibodies will be prepared against the isolated diphtheria toxin-
binding protein(s), as well as to the toxin receptor on Vero cells,
to determine whether the diphtheria toxin-binding protein(s)
corresponds to the toxin receptor.  These monoclonal antibodies
will also be utilized to investigate the cell surface distribution
and mechanism of internalization of the toxin receptor on Vero
cells, as well as to investigate the location and physiological state
of the receptor under conditions where it lacks toxin-binding
capacity (e.g. NaF, vanadate, or TPA treatment).  The gene that
codes for the toxin receptor will be cloned, sequenced, and will be
employed to transfect toxin-resistant mouse L-cells in order to
determine whether toxin resistance is due to lack of receptor
expression.

The results of this proposed project will provide an insight into
the possible nature of the physiological cell surface receptor that
diphtheria toxin utilizes to gain illicit access to the cell cytosol,
will significantly extend our knowledge of toxin:  receptor
interactions, and will further our understanding on receptor-
mediated internalization of such macromolecules as growth
factors, hormones, and other exotoxins.

## Key facts

- **NIH application ID:** 3126852
- **Project number:** 5R01AI016805-11
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **SAM.gov UEI:** YZJ6DKPM4W63
- **Principal Investigator:** LEON EIDELS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $162,183
- **Award type:** 5
- **Project period:** 1980-04-01 → 1992-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126852

## Citation

> US National Institutes of Health, RePORTER application 3126852, STUDIES ON DIPHTHERIA TOXIN AND ITS RECEPTOR (5R01AI016805-11). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126852. Licensed CC0.

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