Some Factors Influencing the Activity of Peroxidase”

An important source and preparation method are reported from the Munich laboratories of WillsGtter (l-3) and his associates who have prepared a highly purified peroxidase from horseradish. The methods of Willstatter, with certain modifications, were employed in the present investigation. About 14 pounds of horseradish roots were cleaned, sliced thin, and self-dialyzed in running water for 8 days. The slices darkened and, in confirmation of WillstSter’s statement, those which developed a deep brown color throughout the slice gave the best yields. After dialysis the slices were freed from water; the enzyme was “set” with oxalic acid; the solid was finely ground, and the enzyme was extracted with barium hydroxide. The enzyme solution was partially purified by treatment with carbon dioxide and with nine-tenbhs its volume of absolute alcohol and the solution rapidly concentrated below 35” in vacua from 1400 cc. to