Article Abstract:
Lipid A was isolated from Porphyromonas gingivalis and subsequently characterized and compared to the LPS of Salmonella minesotta as to its chemical structure and biological activity. Lipid A was found to have unique branched fatty acids with longer carbon-atom chains than those of S. minesotta. It also lacked a phosphate group at the 4' position. The results also revealed that lipid A has an endotoxic activity as demonstrated in various assay systems used. A notable stronger induction of tumor necrosis factor-alpha from the human monocytic cell line compared to that of the mouse cells was observed, indicating that the regulatory mechanisms involved in the process between the two cell types are different.
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Article Abstract:
Research was conducted to determine the mechanism of action of the lipid A-associated proteins (LAPs) of endemic bacteria isolated from the major periodontophathogen, Porphyromonas gingivalis. All contaminating lypopolysaccharides (LPS) were removed from the LAPs preparation using a polymyxin B affinity column. The failure to demonstrate the inhibition of Porphyromonas gingivalis-LPS with the agents indicated that the binding of polymyxin B to P-LPS does not inhibit the biological activity of P-LPS.
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Article Abstract:
Comamonas testosteroni lipid A and its endotoxic properties are discussed. C. testosteroni is an aerobic, Gram-negative rod that grows on testosterone, and its lipid A is very homogeneous vs other naturally produced lipid As. It appears that the composition of 3- hydroxydecanoic acid is not responsible for the low endotoxicity of lipd A seen in the genus Rhodopseudomonas.
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