Chromatographic fractionation of Aspergillus endotoxins

Summary Crude preparations of the endotoxins extracted from the mycelia ofAspergillus fumigatus andAspergillus flavus, after preliminary concentration by ammonium sulfate, have been fractionated by column chromatography on DEAE-cellulose. Although the biological activity of the chromatographed preparations was not limited to a single fraction, examination of the most active fractions by starch gel electrophoresis showed no bands common to the two nephrotoxins.The highest hemolytic and toxic activities of the fumigatus toxin were found in different fractions of the chromatographed material, and starch gel electrophoresis showed no bands common to these two fractions.The molecular weight of the flavus toxin has been estimated to be in the range of 32,000 to 34,000 as judged by the results of ultracentrifugation and microelectrodialysis in starch gels of the most toxic fractions.Both of the toxins have been shown to contain small amounts of hexosamine and larger amounts of non-amino sugars.Presented in part at the 46th Annual Meeting of the American Society of Biological Chemists, Atlantic City, New Jersey, April, 1962.     

Chromatographic fractionation of histones on Bio-Gel P.

Chromatography of histones on columns of polyacrylamide beads (Bio-Gel P) was studied to determine what factors influence separations. The fractionation achieved on eluting with dilute HCl depends on the HCl concentration, the temperature, and a variable characteristic of the gel which is independent of its pore size and mesh. Somatic histone will be eluted in three, four, or five separate fractions, depending on these variables. Retardations of histones that apparently result from interactions between their charged groups and those of the gel have a strong influence on resolution between different types. Certain histones are retarded more than others when the HCl concentration or temperature is lowered or if the gel has been hydrolyzed. Increases in retardation lead to resolution of more fractions; but if too extreme, coelution of the most retarded fractions will occur.     

Human serum protein fractionation by gel filtration

The development of a quantitative immunological technique using polyvalent antiserum permits a more logical approach to the fractionation of complex protein mixtures. In this study whole serum was separated by conventional gel filtration and the fractions obtained were analysed. This demonstrates over 60 immunologically distinct serum proteins. Because the current terminology is inadequate to describe this number of proteins, a temporary numerical nomenclature has been used.