Relation of structure to function for the US reference standard endotoxin after exposure to /sup 60/Co radiation
The structure and function of the highly purified US 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:
- National Institutes of Health, Bethesda, MD
- OSTI ID:
- 5805480
- Journal Information:
- J. Infect. Dis.; (United States), Vol. 1
- Country of Publication:
- United States
- Language:
- English
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560111* - Radiation Effects on Biochemicals- In Vitro- (-1987)