TURBIDIMETRIC CHANGES ACCOMPANYING THE INTERACTION OF ENDOTOXIN AND THE ALPHA-CHAINS OF HUMAN HEMOGLOBIN.

Setlow, Peter (Brandeis University, Waltham, Mass.), Lawrence Levine, and Helen Van Vunakis. Turbidimetric changes accompanying the interaction of endotoxin and the alpha chains of human hemoglobin. J. Bacteriol. 89:1237-1243. 1965.-With the use of a turbidimetric assay, the effects of pH, ionic strength, anions and cations, and varying concentrations of reactants on the interaction of Escherichia coli endotoxin (prepared by the Boivin procedure) with the alpha chain of hemoglobin were studied. The reaction was found to be partially reversible by addition of NaCl or by addition of an excess of either reactant. The characteristics of the reaction indicated that complex formation between two multivalent molecules had taken place. The formation of the complex was inhibited by endotoxin (prepared by the Westphal procedure) and by the products which resulted from partial tryptic digestion of alpha chain.