Advances in Protein Chemistry

Abstract

THE structure of proteins is probably the most Jvumpapant and possibly the most difficult of the maflpr uifeolved problems of chemistry, at least for the immediate future, and coming at a time when preparations are being made in numerous places to storm this citadel, the present volume is very timely since it gives clear reviews of many of the new methods which will be employed. It reflects the present trend of protein research towards exact analysis and what one might call the ‘classical’ organic approach to the problem. The X-ray method has clear possibilities, but they are more limited and at the same time involve greater difficulties than was originally expected. In his excellent survey of this field, I. Fankuchen sums up the position with regard to crystalline proteins as follows. “Single protein crystals can be made to yield exceedingly detailed X-ray diagrams and yet one must admit that to date the results of such single crystal studies have been disappointing; disappointing because very beautiful and complete data have so far only yielded comparatively meagre results”—a conclusion which broadly coincides with the views expressed in the discussion at the Roentgen celebration in London. It appears that although we can expect definite information about the number and arrangement of protein molecules in the unit cell, a complete structure analysis lies in the distant future; perhaps not a surprising situation when one contemplates the empirical formula recently given by Brand and his co-workers for lactoglobulin, one of the few cases in which the analyses approach finality, namely, C1864 H3012 N468 S21 O576, or particularizing the amino-324 acids by easily recognisable abbreviations, as follows: Gly8 Ala29 Val21 Leu50 Ileu27 Pro15 Phe9 CySH4 (CyS)8 Met9 Try4 Arg7 His4 Lys33 Asp36 Glu24 (Glu-NH2)32 Ser20 Thr21 Tyr9 H2O4! It might perhaps not unfairly be said that the chief contribution of the X-ray studies has been to demand and stimulate more accurate analyses. Advances in Protein Chemistry Edited by M. L. Anson John T. Edsall. Vol. 2. Pp. xiii + 443. (New York: Academic Press, Inc., 1945.) 6.50 dollars