Question

A tetrapeptide and a heptapeptide of glutamic acid have been bind to an anion exchange cloumn by using a buffer of ph 6 elution is now started by lowering the ph gradually which of the two peptides will wlute first

Answer 1

Answer:

Publisher Summary

The chapter presents a summary of recent experiments on the column chromatography of peptides and a description of the current status of chromatography as a method for purifying proteins. Columns of ion exchange resins have received particular attention because they were shown to yield quantitative results with amino acids, and hence would be expected to separate peptides quantitatively as well. In addition, such columns are not sensitive to the presence of neutral salts, and can thus be used directly for the analysis of physiological fluids or tissue extracts. When amino acids are chromatographed on sulfonated polystyrene resins, separations of peptides depend upon the affinity of the resin for both the ionic and the nonionic portions of the molecules. The great usefulness of paper chromatography for the separation of peptides has led to several attempts to extend the principles of liquid-liquid or liquid-gel system to columns packed with cellulose or starch. In the study of protein chromatography, many of the laboratory procedures employed are similar to those devised for experiments with amino acids and peptides. The actual protein concentrations can be calculated only if the ninhydrin color values per milligram or the extinction coefficients of the individual proteins are known. Successful chromatography requires that the proteins move down a column as discrete zones and give rise to relatively sharp and symmetrical peaks on an effluent curve. The chapter explores that sulfonic acid resins are employed in two quite different ways in the course of protein purifications.