Modification of the chemical composition and structure of the US Reference Standard Endotoxin (RSE) by /sup 60/Co radiation
A highly purified bacterial lipopolysaccharide (LPS) preparation was exposed in water to megadoses of ionizing radiation from a /sup 60/Co source. As evidenced by electrophoresis, the radiation treatment progressively degraded the lipopolysaccharide molecules by removing first the O-side chain units and then components of the R-core. Chemical analysis of the irradiated (LPS) preparations showed that, in accord with the structural changes, the most profound effects of ionizing radiation occurred in the hydrophilic oligo/polysaccharide moieties (R-core and O-side chain). Progressively higher doses of radiation degraded the simple sugars in decreasing order of galactose, galactosamine, glucosamine, glucose, and heptose. The R-core component 2-keto-3-deoxyoctonate was the most resistant sugar derivative to ionizing radiation. Due to its central position in the LPS aggregates in water, even at comparatively high doses of radiation the hydrophobic lipid A moiety of endotoxin was less affected than the sugar components. Of the fatty acids of lipid A, however, either partial conversion of beta-hydroxymyristic acid into myristic acid or selective loss of the former occurred. The observed structural and chemical changes of LPS are consistent with the effect of active oxygen radicals of radiolysis. In addition, the extensive physicochemical changes explain the altered biological reactivity of radiation-treated endotoxins.
- Research Organization:
- National Institutes of Health, Bethesda, MD
- OSTI ID:
- 5528989
- Journal Information:
- Radiat. Res.; (United States), Vol. 3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Physical and biological properties of U. S. standard endotoxin EC after exposure to ionizing radiation
Relation of structure to function for the US reference standard endotoxin after exposure to /sup 60/Co radiation, Interim report, September 1984-December 1985
Related Subjects
ENDOTOXINS
BIOLOGICAL RADIATION EFFECTS
MOLECULAR STRUCTURE
LIPOPOLYSACCHARIDES
CALIBRATION STANDARDS
CHEMICAL ANALYSIS
COBALT 60
DOSE-RESPONSE RELATIONSHIPS
ELECTROPHORESIS
ESCHERICHIA COLI
WATER
ANTIGENS
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CARBOHYDRATES
COBALT ISOTOPES
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIPIDS
MATERIALS
MICROORGANISMS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
POLYSACCHARIDES
RADIATION EFFECTS
RADIOISOTOPES
SACCHARIDES
STANDARDS
TOXIC MATERIALS
TOXINS
YEARS LIVING RADIOISOTOPES
560111* - Radiation Effects on Biochemicals- In Vitro- (-1987)