Do tumor proteins contain d-amino acids? A review of the controversy.

F. Kögland H. Erxleben in 1939 (30). In this work evidence was presented that tumor proteins con tain certain n-amino acids, particularly n-glutamic acid. These findings have not been generally con firmed, and a controversy arose which has con tinued to the present. The dispute exists almost entirely between the school of Kögl, a vigorous and able protagonist, and an impressive array of equal ly vigorous and able dissenters. While it appears to the reviewer that the weight of evidence is still against the view of Kögland his collaborators, the recent publication of new and challenging positive evidence from the Kögllaboratory makes this problem timely again. The following review is of fered in the hope that it will enable oncologists to follow this important controversy more easily as further developments occur. THE OCCURRENCEOF D-AMINOACIDS IN NA TURE.—Dueto the initial efforts of Emil Fischer and to the extensive studies of Freudenberg, Kar rer, KÃ1⁄4hn, and many others, it appears today that all of the amino acids found in the proteins of nor mal tissues have the same arrangement of substituents about the asymmetric a-carbon atom.1 These amino acids belong to the group convention ally termed the "L" series. Indeed, so great did the