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Book Review Crystallographic Methods and Protocols. (Series Methods in Molecular Biology. Vol. 56). Edited by C. Jones B. Mulloy and M. R

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BOOKS
Organometallics in Synthesis - A
Manual. Edited by M . Srhlosser.
Wiley, Chichester, 1994. 603 pp.,
hardcover S 60.00.-ISBN
0-47193637-5
Two of the most interesting publications of recent years in the field of
organometallic chemistry are the second
edition of Comprehensive Orgunometallic
Chemistry and the book under review
here, Organometallics in Synthesis, edited
by Manfred Schlosser. The difference between the two books could hardly be
greater: on the one hand a 14-volume “encyclopedia” of organometallic chemistry
with many thousands of pages, on the
other hand a manual covering the most
important recent developments in the
field in just over 600 pages. Schlosser’s
book is intended mainly for the newcomer
to the area, who has scarcely any knowledge of the basic principles and working
techniques. The approach is rather similar
to that of Best Synthetic Methods, first
providing the reader with an understanding of the fundamental reaction mechanisms, then following this up with practical advice, rules of thumb, and, most
importantly, carefully chosen laboratory
recipes, so as to enable the novice to successfully synthesize organic compounds
using organometallic reagents. The choice
of examples has necessarily been restricted to what are described in the preface as
the “most popular metals and methods”.
To achieve this goal the editor has assembled a team of well qualified authors,
whose names are inseparably associated
with this field of study. In Chapter 1 (166
pp.) M. Schlosser describes the use of
organometallic compounds of the alkali
metals in synthetic applications. This is
followed by a short chapter (28 pp.) in
which the industrial chemists F. Totter
and P. Rittrneyer discuss the handling and
industrial applications of organolithium
compounds. Chapters 3 and 4 (88 and 100
pp. respectively) provide detailed treatments of the synthetic applications of titanium compounds (by M. T. Reetz) and
organocopper reagents (B. H. Lipshutz).
Chapter 5, by L. S. Hegedus (77 pp.), is
devoted to palladium-catalyzed reactions,
and this is followed by three shorter chapters, dealing with organoboron chemistry
(Ch. 6, 48 pp., by K. Smith), organoaluminum compounds (Ch. 7 , 2 5 pp., H. Yamamoto), and organotin chemistry (Ch.
8, 44 pp., H. Nozaki). The book is completed by a detailed subject index and a
very useful formula index, which enables
one to compare different organometallic
species. All the chapters have comprehensive bibliographies. which in some cases
2682
3> VCH
cover publications up to very recent dates.
The visual quality of the book is excellent:
a consistent typeface has been used
throughout, and the structural formulas
have been very carefully drawn.
Does “Schlosser” achieve its declared
aim of helping the novice to overcome the
psychological and practical barriers to
getting started in organometallic chemistry? Well, to begin with, it comes as no
surprise that in a multiauthor work of this
kind the contributions vary considerably
in both length and quality. I liked especially the chapters on titanium, copper,
and boron compounds and their reactions, not least because they contain a
wealth of practical advice and laboratory
recipes (in the chapters by Lipshutz and
Smith the procedures have been blended
into the text in a very successful way). All
three chapters cover not only “classical”
applications in chemo-, regio-, and
stereoselective reactions but also many
important recent developments. Examples of these include the use of chiral
organotitanium catalysts for enantioselective additions and cycloadditions, and
the preparation of organocopper reagents
with complex structures by transmetallation from organozinc, organoaluminum,
and organozirconium compounds. However, in the copper chapter on page 199 an
error with possibly serious consequences
has crept in: only one half of the quantity
of methyllithium needed for the preparation of the cuprate is shown, so that instead of Me,CuLi one would obtain
methylcopper, which is unstable in its
pure form and could decompose explosively during the subsequent removal of
the solvent!
The chapter on the industrial applications of organolithium compounds does
not, of course, contain laboratory recipes,
but there is much useful advice concerning
the stability and handling of these
reagents. On the other hand, the rest of
the chapters are, in my view, not quite so
good as those just mentioned. In particular, Schlosser seems to have given way to
the temptation to devote a disproportionate amount of space to his own field of
research, as the chapter on organic compounds of alkali metals contains many details and anecdotes of a marginal kind
that are unlikely to be very useful to the
intended readers. In contrast, the chapters
on palladium-catalyzed reactions and
organoaluminum and organozinc compounds contain little in the way of practical advice; these are more like abbreviated
monographs, and the few laboratory
recipes that have been grafted on sit uneasily in these chapters. It is also doubtful
whether the claim to cover the “most
Ver~ugsgesellsc~~u~i
mhH, 0-69451 Wt.rtiliab,i, 1996
popular metals and methods” is fully justified. With a better organization of the
contents it would certainly have been possible to include some more metals, for example by covering organozinc reagents,
which are important in stereoselective
synthesis (e.g., the work of Noyori et al.),
and are also compatible with a wide variety of functional groups (as shown by
Rieke and Knochel). However, the preface promises that there will eventually be
a second, enlarged edition covering these
topics.
Notwithstanding these criticisms, I was
left with a very good impression of
“Schlosser”, and one hopes that the weaknesses will be remedied in a new edition in
due course. N o chemist seriously interested in synthetic applications of organometallic reagents can afford to be without
this book.
Norbert Krause
Institut fur Organische Chemie
und Biochemie
der Universitat Bonn
Bonn (Germany)
Crystallographic Methods and Protocols. (Series: Methods in Molecular
Biology. Vol. 56). Edited by C. Jones,
B. Mulloy and M . R. Sanderson.
Humana Press, Clifton, NJ, 1996. 394
pp., loose-leaf edition $69.50.ISBN 0-896-03259-0
This publication is intended as a “recipe
book” for protein crystallographers. It
gives information about practical laboratory procedures that cannot be found in
ordinary textbooks. Cryocrystallographic
methods, which are becoming ever more
important, are described in practical detail, as also is the installation and operation of different types of commonly used
area detectors. The book gives details of
computer programs for processing X-ray
diffraction data and determining and
refining protein crystal structures. The use
of such programs is explained clearly and
in sufficient detail to enable even the
novice to succeed in getting results. The
information provided here is normally
only available in the dedicated handbooks
supplied with the relevant hardware and
software, and it should also be helpful
in choosing and buying equipment. The
book describes strategies for determining
the positions of heavy atoms, which are
needed for phase determination, and gives
protocols for refining a structure once it
has been solved. All these working procedures (“recipes”) are described clearly and
in detail, so that the reader with a back-
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Anzeii.. Chetn. Int. Ed. Engl. 1996. 35, Nu. 22
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ground in molecular biology o r biochemistry and an interest in structural biology
can quickly master the methods. The final
part of the book describes methods for
crystallizing oligonucleotides, proteinD N A complexes, viruses, and membrane
proteins.
The contents are clearly arranged, and
all the chapters have been written by internationally recognized experts. In the first
chapter (“Introduction”), the fundamentals of protein crystallography are briefly
explained. Next, in “Overexpression, Isolation and Crystallization of Proteins”,
the production of proteins in prokaryontic and eukaryontic overexpression systems and their isolation and purification
are described. followed by strategies for
obtaining suitable crystals by “screening”
and improving the process by seeding.
Under the heading “Preliminary Characterization of Crystals”, the subject of crystal symmetries is introduced, followed by
the “mounting” of crystals in capillaries
and the shock-freezing process used in
cryocrystallography. The recording and
evaluation of precession patterns to yield
information on space groups and cell constants is then described. The chapter
“Modern Methods for Rapid X-Ray Diffraction Data Collection from Crystals of
Macromolecules” introduces the area
detectors that are now generally used,
and gives a clear and detailed description
of their manner of operation and the
processing and reduction of the data.
Here the subject of cryocrystallography is
again addressed. The next chapter has the
title ”Use of Multiple Wavelength
Anomalous Diffraction (MAD) Measurements in a b initio Phase Determination
for Macromolecular Structures”. An introduction to the theory of anomalous
dispersion leads into an account of how
data recorded a t different wavelengths using a synchrotron source are analyzed to
determine phase angles. The chapter on
“Structure Determination Using Iso-
morphous Replacement” describes the
preparation of heavy-atom derivatives,
the use of Patterson methods to determine
the positions of the introduced atoms, and
the final refinement of these positional
data. Various criteria used in the calculations are discussed, such as the “figure of
merit”, the Cullis R-factor, and the “lack
of closure error”, as also is the use of Patterson difference and Fourier difference
methods. In “Molecular Replacement Using Known Structural Data” the reader is
introduced to these methods, which are
becoming increasingly important as a result of the continuing growth of protein
data banks. The various programs of importance for rotation and translation
methods are clearly described and their
use is illustrated by examples of practical
applications. Next is a chapter on “Density Modification in X-Ray Crystallography”, describing the very effective methods based on this principle which can
improve the initial electron density distribution, thus facilitating comparison with
model predictions. The chapter “Refinement of Protein and Nucleic Acids Structures” discusses the most recently developed programs whereby the refinement
can be carried out more effectively, describes their applications, and sets out
protocols. Methods are also described
whereby models are first constructed
manually and subsequently improved;
these can be used alternately in conjunction with refinement procedures. The
chapter ends by discussing quality criteria
that can be applied to a structure model,
such as the R-factor and the free R-factor.
The latter topics are treated in greater
depth in “Recent Developments for Crystallographic Refinement of Macromolecules”, where the methods are described in detail. as also is the use of
“simulated annealing”.
The next four chapters are devoted to
methods for preparing crystals and determining the structures of oligonucleotides,
BOOKS
protein -DNA complexes. viruses, and
membrane proteins. These chapters form
a very useful extension to the crystallization protocols for proteins that were
described at the beginning of the book.
I regard the tables listing the oligonucleotides, protein-DNA complexes, and
viruses that have so far been crystallized,
together with the protocols used to
achieve the crystallization. as a valuable
and important resource. The particular
problems that arise in the crystallization,
data collection, data processing, and
structure determination for molecules of
this type are discussed. Special attention is
given to the difficulties caused by noncrystallographic symmetry and phase
broadening in analyzing the structures of
viruses. The final chapter is mainly concerned with the two-dimensional crystallization of membrane proteins; in addition there is a discussion of methods for
growing three-dimensional crystals, with
references to the relevant literature so that
the interested reader can pursue this aspect in more detail. However. a list of the
commonly used detergents would have
been a useful addition.
This book fills a gap in the literature on
protein crystallography, as the main emphasis here is on the practical matter of
protocols for analyzing protein crystal
structures rather than on the theoretical
fundamentals. It can be recommended not
only for biochemists and molecular biologists who wish to learn and apply the
methods of protein crystallography, but
also for experienced protein crystallographers, who will find in it a very good
overview of the subject and many useful
ideas and tips in relation to their work.
Accordingly, I have just ordered three
copies of the book for my research group.
W~tlfrumSuengev
Institut fur Kristallographie
der Freien Universitat Berlin
Berlin (Germany)
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