THE ACTION OF $gamma$-RAYS ON SODIUM DEOXYRIBONUCLEATE IN SOLUTION. III. DENATURATION

Journal Article · Tue Aug 16 04:00:00 EDT 1960 · Proc. Roy. Soc. (London)

DOI:https://doi.org/10.1098/rspb.1960.0089· OSTI ID:4177821

Peacocke, A R; Preston, B N

The displacement of the titration curves at 25 deg C of herring sperm sodium desoxyribonucleate (DNA) irradiated in solution by gamma rays was confirmed. Values for the mean extent of denaturation deduced from such curves agree with those obtained from the reversible titration curves that DNA exhibits at --0.7 deg C. One effect of gamma irradiation was to displace these reversible curves asymmetrically in a manner which suggested that the hydrogen bonds linking adenine and thymine were more susceptible to rupture by gamma irradiation than were those which link cytosine and guanine. The logarithm of the fraction of titratable groups in helical regions of the DNA was a decreasing linear function of radiation dosage and the significance of this observation is discussed. In the first stages of irradiation, the rupture of cross-linking hydrogen bonds is very efficient and has a G value of thirty-eight base-pairs severed per 100 ev. (auth)

• Research Organization: Univ. of Birmingham, Eng.
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-021518
• OSTI ID: 4177821
• Journal Information: Proc. Roy. Soc. (London), Journal Name: Proc. Roy. Soc. (London) Vol. Vol: 153B
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ADENINE
BONDING
CHEMISTRY
CYTOSINE
DECOMPOSITION
GAMMA RADIATION
GUANINE
HETEROCYCLICS
HYDROGEN
NUCLEIC ACIDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RADIATION DOSES
RADIATION EFFECTS
SOLUTIONS
THYMINE
VITAMIN B-4
VITAMINS