# DIRECT IONIZATION EFFECTS IN DNA

> **NIH NIH R01** · GEORGIA STATE UNIVERSITY · 1991 · $76,733

## Abstract

lt is generally agreed that the biological consequences of ionizing
radiation originates with effects of the radiation on DNA.  lt is
also generally agreed that the indirect effect of attack by
hydroxyl radicals from water radiolysis is responsible for a
significant portion of the consequences.  However, less agreement
exists on the identities of the significant products of direct DNA
ionization.  Since existing evidence indicates that direct effects
are roughly as important as indirect ones, the long-range
objectives of this work are to identify the mechanisms, and to help
clarify the importance, of direct ionization effects in DNA.

The specific aims for this project, derived from existing evidence
and models reported in the literature, are: (1) to continue the
effort to identify and characterize the primary products of purine
derivatives, and to characterize their subsequent products:  (2)
to investigate the character (variability of methyl coupling,
protonation state, and effect of hydration) of thymine anions in
a variety of systems;  (3) to investigate factors which may control
the elementary protonation and deprotonation reactions of the
primary ions; (4) to investigate the role of "bound" water in
determining the identity and chemical behavior of the primary ionic
products; (5) to investigate systems in which more than one base
is present in order to clarify mechanisms in which anions and
cations may appear preferentially among the constituents of a
system.

To meet these aims, a variety of experiments will be performed
using well characterized molecular systems (single crystals), and
focusing on the radical (paramagnetic) products of ionization
events.  The main experimental procedures will be those of high
resolution magnetic resonance spectroscopy (ENDOR), associated with
temperature control (below 10 K to 300 K).

## Key facts

- **NIH application ID:** 3174390
- **Project number:** 5R01CA036810-06
- **Recipient organization:** GEORGIA STATE UNIVERSITY
- **SAM.gov UEI:** MNS7B9CVKDN7
- **Principal Investigator:** WILLIAM H NELSON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $76,733
- **Award type:** 5
- **Project period:** 1986-04-01 → 1994-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3174390

## Citation

> US National Institutes of Health, RePORTER application 3174390, DIRECT IONIZATION EFFECTS IN DNA (5R01CA036810-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3174390. Licensed CC0.

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