Oxidation of macrophage membrane cholesterol by intracellular Rhodococcus equi.

Phagocytic uptake by cultured mouse macrophages (PD388D1) of a virulent strain (ATCC 33701) of Rhodococcus equi producing substantial cholesterol oxidase was accompanied by intracellular survival of the bacteria, and enzymatic oxidation of macrophage membrane cholesterol. A non-virulent strain (4219) lacking cholesterol oxidase was largely eliminated from the macrophages and did not bring about oxidation of membrane cholesterol. When R.

Some aspects of the history of membrane-damaging toxins.

In this review the following topics are considered: (a) the character of biomedical research and how it has changed during the last six decades; (b) the early history of membrane-damaging toxins; (c) comparative toxinology as illustrated by similarity of the toxins of the brown recluse spider and the bacterial agent of peudotuberculosis, and by similarity of a toxin of a sea anemone and the thiol-activated membrane-damaging agents of bacteria; (d) examples of the diversity of membrane-damaging toxins; (e) cooperative or synergistic lytic systems; and (f) the outlook for the future.

Characterization and amino acid sequences of two lethal peptides isolated from venom of Wagler's pit viper, Trimeresurus wagleri.

Two lethal toxins were isolated from Trimeresurus wagleri venom by fast protein liquid chromatography (molecular sieve) and high performance liquid chromatography (reverse phase). The toxins (termed peptide I and II) had mol. wt of 2504 and 2530, respectively, pIs of 9.

Cytotoxicity of cholesterol oxidase to cells of hypercholesterolemic guinea pigs.

1. A high cholesterol diet caused guinea pig erythrocytes to become sensitive to lysis by cholesterol oxidase (CO), a protein not hemolytic to normal cells. 2.

Kinetics of hemolysis induced by a toxin from Bacillus thuringiensis israelensis.

The kinetics of hemolysis resulting from the action on rabbit erythrocytes of a highly purified cytolytic toxin (26,000 mol. wt) isolated from a spore-crystal mixture of Bacillus thuringiensis israelensis was studied. Course of hemolysis, as determined by release of hemoglobin, yielded sigmoid curves whose maximum slopes were taken as a measure of the rate of lysis.