Human leukocyte photoreactivating enzyme

Journal Article · Wed Jan 01 04:00:00 EST 1975 · Basic Life Sci.; (United States)

DOI:https://doi.org/10.1007/978-1-4684-2895-7_14· OSTI ID:7210088

Sutherland, B M

A photoreactivating enzyme from human leukocytes has been isolated and characterized. The enzyme requires DNA irradiated with ultraviolet light (220 to 300 nm) as substrate, and visible light (300 to 600 nm) for catalysis. In the reaction, the enzyme converts cyclobutyl pyrimidine dimers in the DNA to monomer pyrimidines. The enzyme has an apparent monomer molecular weight of 40,000 and tends to form aggregates. The pH optimum of 7.2 and absence of a requirement for metal ions are similar to the requirements of the Escherichia coli enzyme; however, the ionic strength optimum of 0.05 is much lower than those for other photoreactivating enzymes. The demonstration that human cells possess photoreactivating enzyme implies that a direct test by photoreactivation may be made of the role of pyrimidine dimers in the induction of abnormal cell growth.

• Research Organization: Univ. of California, Irvine
• OSTI ID: 7210088
• Journal Information: Basic Life Sci.; (United States), Journal Name: Basic Life Sci.; (United States) Vol. 5A; ISSN BLFSB
• Country of Publication: United States
• Language: English

Related Subjects

560151* -- Radiation Effects on Animals-- Man
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BLOOD
BLOOD CELLS
BODY FLUIDS
DNA
ELECTROMAGNETIC RADIATION
ENZYMES
LEUKOCYTES
MAMMALS
MAN
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PHOTOREACTIVATION
PRIMATES
RADIATION EFFECTS
RADIATIONS
REPAIR
ULTRAVIOLET RADIATION
VERTEBRATES
VISIBLE RADIATION