Protein Stability and Stabilization Through Protein Engineering

Protein Stability and Stabilization Through Protein Engineering Ellis H o r w o o d

Series in B i o c h e m i s t r y a n d B i o t e c h n o l o g y

Yoshiaki Noshoh and Takeshi Sekiouchi Ellis Horwood, New York and London, 1991, pp. 224, £59.50 The mechanism of protein chains folding into compact, defined structures, how such structures are stabilized and how their stability can be changed, has been a topic for discussion, experiment and theorizing for a considerable time. This book attempts to take stock of the current understanding of these processes and offers some advice regarding future fruitful directions along which to proceed. The text starts with a review of known protein structural principles and the forces of interaction: dispersive, electrostatic, van der Waals, hydrogen bonding and the currently popular hydrophobic interactions, and the types of architecture discovered (secondary, tertiary and quaternary - I find these terms so old-fashioned) followed by a few pages on structure prediction. This represents about a third of the book. Protein stability is introduced by a brief discussion of the thermodynamics of unfolding and the stabilizing forces. This paves the way for a discussion of stable

proteins, enzymes from thermophilic bacteria which can function over a temperature range - 5 ° C to 100°C. A number of examples are discussed in the context of hydrophilieity, rigidity, hydrogen bonding and other interactions and the reader is left with the impression that no one really knows, apart from the bland statement that it is because AH is superior (sic) to T AS! Chapter 5 tackles stabilization through chemical and physical modifications following three strategies: (1) amino acids chemically modified, (2) the protein itself immobilized (bound or trapped), and (3) site-directed mutagenesis. The latter procedure is developed in the subsequent chapter and represents a decent slice of the book covering a series of examples in two categories--where the protein structure is known or unknown: examples are T4 phase lysozyme; subtilisin BPN'; dihydrofolate reductase; 2 repressor; ribonuclease; neutral protease from B. stearothermophilus;thermus aquaticus protease; ~-subunit of tryptophan syn-

thase. The final chapter offers a critical review of methods used, future trends and favours site-directed mutagenesis as an important way forward. Each chapter ends with a respectable list of useful references, most of which cover developments during the 1980s. One is left with the impression that there is still much to understand in this field. The book is written in a gentle, easy to read style with many references should one wish to chase up the details or background to any result or interpretation. The authors discuss protein stability from both a molecular and a physicochemical point of view. The text will be useful to researchers and postgraduate students in biochemistry, biotechnology, protein engineering, enzymology and enzyme technology together with research workers in agricultural chemistry and pharmacology using enzymes and proteins. Edward Atkins

Macromolecular Structures 1991 Edited by W. A. Hendrickson and K. Wfithrich Current Biology Ltd, London, 1991, £90, pp. 150 This impressive text summarizes the atomic structures of biological macromolecules reported in 1990. The need for such a compendium is a consequence of the increasing number of detailed atomic structures of complicated macromolecules being reported, of the order of a few hundred for 1991. In order for researchers to be kept abreast of structural developments and for those searching for trends in biopolymer design, structure and architecture it is necessary to have a convenient summary of the salient structural features that are being discovered as and when they occur. Subsequent volumes will cover structure reports in successive years. The text encompasses those structures that are described as three-dimensional atomic models, that are greater than 10 oligonucleotides, 20 polypeptides or 5 oligosaccharides. The structures are deduced by X-ray diffraction and/or

electron diffraction and multidimensional n.m.r. In this issue, of the 210 structures summarized, 200 are proteins and 10 are nucleic acids (-t-proteins/drugs). The format for each structure is that the basic information--reference source, biological source, structural parameters, modelling, quality of structure and references--is listed on the left hand page. On the right hand page is a paragraph on the biological context followed by a structure description with illustrations, many in colour and often reproduced as stereo pairs. It is hoped that journals and/or referees will demand tables of coordinates and structures to be deposited at the Brookhaven protein data bank so that the considerable number of NR (not reported) values in these summaries is reduced. I like the compact presentation of the structural details, the high quality of the page finish and the large size of the pages

(,,,28 cm x 21 cm). With the increasing number of structures being elucidated these reports will become a necessary part of structural biology of macromolecules. Akin in some respects, to the structural reports for small molecules, I judge that in future, authors will appreciate the advantages of colour reproduction as they find their structures juxtaposed and compared with related biological macromolecules and this will encourage more uniform and higher standards of illustrations. At £90 it is not meant (I presume) to be purchased by individuals but for research groups involved in the structural biology of macromolecules and for university, institute and industrial libraries. This, and successive editions, will become a necessary part of the reference section in these libraries. Edward Atkins

Int. J. Biol. Macromol., 1993, Vol. 15, O c t o b e r

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