The glutamic acid of normal and malignant tissue proteins

KOGL & ERXLEBEN [1939, 1] have recently put forward the suggestion that partial racemization is a characteristic of the proteins of malignant tissues. The claim is based on their observation that a normal tissue such as calf lung, when submitted to a short acid hydrolysis, gave a series of amino-acids, all of which, after isolation, showed under standard conditions the normal rotation, whereas a few of the corresponding products from malignant tissues were found to be partially racemized. This difference was particularly striking in the case of glutamic acid. From normal lung and normal heart tissues they obtained, in what appeared to be good yields, the usual l-(+)glutamic acid showing, in 9 % hydrochloric acid, the normal rotation of [CXID + 31-60. Corresponding pre- parations from an ovarian tumour, from an ovarian carcinoma and from two different mammary carcinomata, on the contrary, showed rotations of [oc]D+21.80, + 4.60, + 11.60 and + 16-1, indicating that they contained 15-6, 42-7, 31-7 and 24-6 % respectively of d-(-)glutamic acid.