Configuration of Glutamic Acid Isolated from Subacute Lymphatic Leukemic Tissue Proteins

Abstract

The exact relationship of leukemia to neoplastic disease has not been determined. The following types of human neoplasm, when examined by the procedure used by Kögl and Erxleben, 1 have been reported to yield partly racemized glutamic acid : 2 carcinoma of the ovary, carcinoma of the breast, adenocarcinoma of the colon, and sarcoma of the thigh. Normal human tissues (ovaries, colon) have been reported to yield only 1 (+)glutamic acid. 2

We have isolated glutamic acid from the liver and spleen of a patient who died of subacute lymphatic leukemia. Microscopic examination revealed that at least 20% of the liver, and 30% of the spleen, were composed of leukemic areas. Major portions of these organs removed at autopsy were placed in alcohol. Following transport to the laboratory, the tissues were finely minced, after which they were covered with 0.1 N hydrochloric acid and heated several hours on the steam bath until a majority of the material had gone into solution. Sufficient trichloracetic acid then was added to make a concentration of 10%. The precipitated proteins were filtered off, washed and extracted several times with hot alcohol in order to remove trichloracetic acid. The proteins were dried at 110° and lipids partly were extracted with boiling ether. Hydrolysis and isolation of glutamic acid were then carried out as described by Kogl, Erxleben, and Akkerman. 3 The results obtained are recorded in Table I. No racemic acid was isolated from the leukemic tissues.

As a control, glutamic acid was isolated from protein obtained from a kidney neoplasm (dog). We are indebted to Dr. E. T. Bell, Head of the Department of Pathology, University of Minnesota Medical School, who examined sections of this tumor and found it to be an undifferentiated sarcoma.