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ROOK REVIEWS The Statistical Approach to X-Ray Structure Analysis. By metabolism brings home the fact t h a t in spite of much work the conversion of tyrosine t o melamine in the mammalian 1-LADIMIR VANDand RAYPEPINSKY.X-Ray and Crystal Analysis Laboratory, Department of Physics, The skin is still incompletely understood. T h e review deals Pennsylvania State University, State College, Pennsyl- with a great variety of subjects, such as the chemical reactions involved in homogentisic acid, thyroxine and adrenalin vania. 1953. m i 98 pp. 21.5 X 28 mi. Price, formation as well as the question of hormonal control of g1.50. melanin formation and the loss of certain enzymes in men This little volume is primarily devoted to a critical esy i t h abnormalities of metabolism of tyrosine and phenylalaamination of the method recently proposed by H . Hauptnine. Sizer deals with a related subject, the action of tyro+ mann and J . Karle for a direct mathematical solution of the inase and peroxidase on proteins. A number of hormones phase problem in crystallography. The procedure involves and enzymes are inactivated by tyrosinase while others are application of the statistical random walk problem to strucnot, though in the latter case there is evidence t h a t they too ture factor equations t o determine the probability of a giveti oxidized. Langenbeck discusses the covalent intermesign assignment. In view of the far reaching consequence are diaries which have been shown t o be formed between cataof such a general solution, this critique will be of lyst (or coenzyme) and substrate in certain non-enzymatic or considerable interest t o X-ray analysts. I t s conteiits are enzymatic reactions. It is believed t h a t the enzyme propresented in a concise manner, appropriately written for tein (apoenzyme) activates the coenzyme and determines those familiar with the various techniques used in solution the specificity of the reaction. Leloir’s article on isomerof the structure problem from X-ray data. ases, mutases and related enzymes is a n excellent resume of IThile the authors emphasize t h a t the Hauptmann-Karle a field to which he has contributed so much by the discovery approach is of considerable value and has given tiem insight of the coenzymes glucose-l,6-diphosphate and uridine dito the phase problem, they present evidence t o show t h a t phosphate glucose. the statistical approach is not reliable except in special Hoffmann-Ostenhof in a long article has again attempted cases and disagree strongly with the claim t h a t i t gi\-es a the impossible, a systematic nomenclature of enzymes. general solution for all centrosymmetric space groups, proThe classification and names of the enzymes are based on vided the number of observed structure factors is sufficiently the reactions catalyzed by them. Trouble arises wheii great. mechanisms are assumed in disregard of experimental eviThe formulas given by Hauptinaiin and Karle are transdence, ; . e . . the starch phosphorylases are lumped with suformed “into a form more suitable for practical computa- crose phosphorylase and called amylose-transglucosidases. tion.” Alternate methods of derivation of the probability Hexokinase would have t o be renamed 4 T P + hexose distribution functions are presented which poiut up the re(rather than glucose) transphosphatase. T h e author writes lation of these equations to Patterson and Harker functions for this enzyme a freely reversible reaction, as he also does and provide a better basis for understanding the meaning and for Q-enzyme, renamed amylose -+ amylopectin transglucoslimitations of the statistical relations. The statistical idaie. I n the reviewer’s opinion our knowledge of enzyme treatment is interpreted as corresponding to a “probability mechanisms is still so incomplete t h a t it is best to desist sharpening” of Patterson peaks with the origin removed; from classifications a5 they are here attempted. this leads to convergence of the structure to that of the highThe Inst three articles deal with related subjects. Desest peaks of a Patterson and hence gives the correct answer iiuellc discusses techniques used in the elucidation of proonl>- if the Patterson function resembles the actual struct e i n structure, Zittle deals mith adsorption of proteins on a ture. A hypothetic21 structure with four atoms in the unit variety of ,substances and the methods of elution. Many cell, space group P I , in which the statistical method does examples of successful chromatographic separation of pronot give the correct result is discussed in some detail. An tein.: are collected. Schwimmer and Pardee deal with analysis of the success of the statistical method in deriving inethods of isolation of enzymes; they state that 72 enzymes the naphthalene structure is presented. h a r e been obtained in the crystalline state. Extension of the statistical treatment has led authors to The volume contains a cumulative index for \Folunies Iiiew functions which give better representations of the XIIT. structure of naphthalene than the conventional projections. I~EPARTMIEZT OF BIOLOGICALCHEMISTRY They suggest t h a t further study will be necessary to show \v.4SHISGTOS UNIVERSITY GERTYT . CORI Ivhether these functions mill be generally useful it1 the deST. I,OUIS, h l I S S O U R I termination of more complex structures. I n their view, honever, the statistical :tpproach in its present form cannot be relied upon t o furnish a correct solution of the phase problem. The Chemical Structure of Proteins. A Ciba Foundation DEPARTMEAT OF CHEMISTRY Symposium held 1st to 3rd December, 1952. Edited by S.I\*.GREGORY G. E. IT, WOLSTENHOLME, Y‘SIVERSITY OF ~VASHIXGTOS O.B.E., M.S., M.B., B.Ch. and SEATTLE 5 , ~VASHISGTON X~ARGARET P. CAMERON, M.A., A.B.L.S. Little, Brown and Company, Boston, Massachusetts. 1954. x 222 pp. 21 X 14.5 cm. Price, $6.00. Advances in Enzymology and Related Subjects of BioThis book comprises the papers and informal general dischemistry. Volume 14. Edited by F. F. SORD, Ford- cussions given at the Ciba Foundation’s symposium 011 ham University, Xew York, S. Y . Interscience Pub“The Chemical Structure of Proteins.” The methods dislishers, Inc., 250 Fifth Avenue, S e w York 1, S.Y . 1953. cussed herein have mainly been developed within the last x 470 pp. lti.5 X 23 ,5 c m Price, 39.25. Few years. The critical discussion of the usefulness and Contributions in thi-, x-olunie froin the United States, specificity of these methods in protein chemistry adds greatly t o the value of this book. Germany, France, Austria : m i the -2rgentine continue t o The first three chapters deal with the purification of promake the “Advancer” a n international journal. Riicher teins, in particular by the methods of column anti partition burveys the difficult problem of energy transport in the living cell. Several theories and models are considered and criti- chromatography. LZany chapters are devoted to a critical cally e\-aluated. A clear style and good organization make survey of C and S end-group analyses, both by chemical and enzymatic means. The problems of the partial hythis a very readable chapter. SIiell and Brown deal with drolysis of proteins and the subsequent separation of the pantethine and related forms in the lactobacillus bulgaricus resultant peptides are also considered. The book ends with factor ( L B F ) . The related forms are mixed disulfides of a discussion of chemical and electron microscope studies on pantethine. Preparation of LBF from culture filtrates, thr structure of collageii. irieritificatioii :itid \b,ntlie\i< :ire dt.w-rilw~l. Patitrthiiie i.: roriiicil f i - o i i i c o c i i z y i i i e A I)? t l i e xctioii of inteqtiiiul l)ho\I Iirse Impers are a l l writteii 1))- anthixitics i t ] tlieir liclil
