Glutamic Acid of Proteins

Abstract

RELEVANT to the discussion which has taken place recently between Chibnall¹ and Kögl and Erxleben^2,3 are some facts which I have accumulated in an analysis of gliadin. Kögl and Erxleben find that the glutamic acid derived from the proteins of malignant tissue is partially racemized and suggest that this might be a characteristic of such proteins. Chibnall found tumour proteins to contain the bulk of their glutamic acid in the ordinary active form with [α]^D + 31·6° in 9 per cent hydrochloric acid, and he thought that any racemization was incidental to the methods employed in its isolation. The work described here indicates that a vegetable protein such as gliadin also contains part of its glutamic acid in a racemic form, and that it is probably a general characteristic of proteins and not of special significance for the proteins of tumours.