Relation of structure to function for the US reference standard endotoxin after exposure to /sup 60/Co radiation, Interim report, September 1984-December 1985
The structure and function of the highly purified U.S. reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a /sup 60/Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain-repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins.
- Research Organization:
- Naval Medical Research Inst., Bethesda, MD (USA)
- OSTI ID:
- 5803544
- Report Number(s):
- AD-A-165068/8/XAB; NMRI-86-1
- Country of Publication:
- United States
- Language:
- English
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ENDOTOXINS
BIOLOGICAL RADIATION EFFECTS
BACTERIAL DISEASES
BIOLOGICAL FUNCTIONS
COBALT 60
ELECTRON MICROSCOPY
ELECTROPHORESIS
LIPOPOLYSACCHARIDES
MOLECULAR STRUCTURE
MOLECULES
MUTAGENS
PARTICLES
SPHERES
ANTIGENS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CARBOHYDRATES
COBALT ISOTOPES
DISEASES
FUNCTIONS
INFECTIOUS DISEASES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIPIDS
MATERIALS
MICROSCOPY
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
POLYSACCHARIDES
RADIATION EFFECTS
RADIOISOTOPES
SACCHARIDES
TOXIC MATERIALS
TOXINS
YEARS LIVING RADIOISOTOPES
560131* - Radiation Effects on Microorganisms- Basic Studies- (-1987)