Loss of covalently linked lipid as the mechanism for radiation-induced release of membrane-bound polysaccharide and exonuclease from Micrococcus radiodurans. [/sup 60/CO]

Journal Article · Sat Aug 01 00:00:00 EDT 1981 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575588· OSTI ID:6314697

Mitchel, R E.J.

The mechanism of ..gamma..-radiation-induced release of polysaccharide and exonuclease from the midwall membrane of Micrococcus radiodurans has been examined. These two components appear to be released independently, but by very similar processes. Direct analysis of radiation-released polysaccharide indicated the absence of an alkali-labile neutral lipid normally present in the native material. Radiation-induced release therefore probably results from the radiolytic cleavage of a covalently linked lipid which normally serves to anchor these substances to the membrane. The absence of a natural membrane-bound carotenoid had no effect on the rate of release of these components. Likewise, the absence of exonuclease in an exonuclease minus mutant did not influence the release of polysaccharide. It is suggested that the major pathway of radical transfer from the initiating .OH and culminating in the cleavage of the neutral lipid anchor may not be via the membrane.

• Research Organization: Atomic Energy of Canada Ltd., Chalk River, Ontario
• OSTI ID: 6314697
• Journal Information: Radiat. Res.; (United States), Vol. 87:2
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CELL MEMBRANES
BIOLOGICAL RADIATION EFFECTS
CHEMICAL BONDS
RADIOLYSIS
LIPIDS
RADIOINDUCTION
CELL WALL
COBALT 60
DOSE-RESPONSE RELATIONSHIPS
GAMMA RADIATION
HYDROXYL RADICALS
MICROCOCCUS RADIODURANS
NUCLEASES
POLYSACCHARIDES
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CARBOHYDRATES
CELL CONSTITUENTS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COBALT ISOTOPES
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ENZYMES
ESTERASES
HYDROLASES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MEMBRANES
MICROCOCCUS
MICROORGANISMS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOISOTOPES
SACCHARIDES
YEARS LIVING RADIOISOTOPES
560131* - Radiation Effects on Microorganisms- Basic Studies- (-1987)