The effect of ultraviolet light and X rays on an enzyme-forming system

Journal Article · Fri Dec 01 04:00:00 EST 1961 · Journal of Cellular and Comparative Physiology

DOI:https://doi.org/10.1002/jcp.1030580424· OSTI ID:4802841

Novelli, G. David; Kameyama, Tadanori; Eisenstadt, J. M.

Ultraviolet irradiation of E. coli cells was found to inhibit the induced synthesis of beta -galactosidase and the inhibition was reversed by photoreactivation. Examination of crude extracts of such cells led to the discovery of a particle-bound fraction of beta -galactosidase. The particlebound enzyme occurs only in the presence of inducer. When inducer is removed, the enzyme leaves the particle and becomes associated with the soluble pool. These observations led to the discovery of a cell-free system that can synthesize the enzyme. The system consists of particles and supernatant, both of which must be prepared from pre-induced cells. The system requires the presence of inducer, a source of energy, amino acids, and the nucleoside di- and triphosphates. Enzyme synthesis is inhibited by chloramphenicol, glucose, ribonuclease and deoxyribonuclease. Ultraviolet treatment of the supernatant yielded an inactive preparation that could be made active by addition of DNA from untreated supernatant. Similarly x irradiation of cells destroyed induced enzyme synthesis and cell-free preparations made from x-irradiated cells were inactive. Such inactive preparations could synthesize enzyme when supplemented with DNA. Only DNA's prepared from cells containing the gene for beta -galactosidase are effective. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• Sponsoring Organization: USDOE
• NSA Number: NSA-16-007458
• OSTI ID: 4802841
• Journal Information: Journal of Cellular and Comparative Physiology, Journal Name: Journal of Cellular and Comparative Physiology Journal Issue: S1 Vol. 58; ISSN 0095-9898
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AMINO ACIDS
ANTIBIOTICS
BACTERIA
BIOLOGY AND MEDICINE
CENTRIFUGATION
CHLORAMPHENICOL
ENERGY
ENZYMES
GALACTOSE
GALACTOSIDASE
GLUCOSE
NUCLEIC ACIDS
PHOTOREACTIVATION
RADIATION EFFECTS
SUGARS
ULTRAVIOLET RADIATION
X RADIATION