Electrophoresis of collagen

Abstract

The electrophoretic mobilities of four collagens and a gelatin were measured. One collagen was prepared from a limed steer hide; the other three were from the fresh hide, t endons, and bones of a steer. The differences between the mobilities are explained in t erms of differences in the amidonitrogen contents of the various preparations. The isoelectric point of the unlimed-hide collagen is at about 7.0 on the pH scale.

Studies on the purification of collagen

“…The results of these measurements are shown in figure 6. The isoelectric points determined by this work agree very well with those found by Beek and Soome [14] and by Highberger [15] on these same materials. In figure 7 the mobility-pH curves are plotted for the hide collagen samples prepared in a manner discussed previously in the text.…”

“…Previous investigators [14] have indicated that the isoelectric point and amide nitrogen content of collagen were related. In table 2 the amide content and isoelectric point are listed for several collagen samples.…”

“…This is probably due to the drastic hydrolysis to which these matcrials were subjected during purification. Beek and Sookne [14] have suggested that the decrease in amide nitrogen content is accompanied by an increase in the number of free carboxyl groups, the net result of which is to shift the isoelectric point to a more acid region. The results obtained with the two bone collagen samples, one of which was treated with trypsin, are similar.…”