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BOOK REVIEWS
degradation in heart and skeletal muscle. The Editor has
managed to bring together contributors who effectively cover
the field. The book contains a general section giving an overview
of protein turnover in mammalian cells, including a discussion of
the regulation and mechanisms of degradation and of the
technical difficulties involved in measurement of protein turnover. Sections dealing with the regulation of degradative
processes cover the classification and characterization of
proteolytic enzymes, the regulation of protein degradation in
heart, the importance of the lysosome to cardiac protein
catabolism and regulation of gene expression during muscle
differentiation and a critical evaluation of protein turnover in
heart and skeletal muscle during normal growth and hypertrophy of muscle. A particularly useful section concerns
pathological degradation of muscle protein in man, an area in
which the results of more basic research on proteinases and
indices of protein degradation, such as 3-methylhistidine
production, have only begun to be applied. It is rather surprising
to consider that almost nothing is known about protein
degradation in man in circumstances of altered muscle mass
such as muscular dystrophy, cachexia, due to cancer, starvation
and infection. The success of scientists in describing many of the
processes in lower mammals and in bacterial systems has not
yet been approached in man, and investigations of human
regulatory mechanisms, except in the broader sense, are
completely lacking. This is not to say, however, that attempts
have not been made to alter protein degradation in different
pathological situations, and this volume contains discussion of
nutritional, hormonal and pharmacological intervention into the
processes of degradation in human skeletal and myocardial
tissue in an attempt to inhibit protein degradation. However, one
type of intervention notably absent from this list is the use of
branched-chain amino acids in total parenteral nutrition as a
means of sparing nitrogen. Indeed, the words ‘branched-chain
amino acids’ figure very little in the discussions, perhaps the only
area of up-to-date interest and controversy which is not covered
in the field.
This volume seems to me to be a welcome addition to a field
in which information is at present widely distributed: it is
extremely well produced, and contains a good index. It ought to
be useful both for established workers in the field and for
graduate students attempting to gain an overall picture of
processes of protein degradation in a tissue which after all
composes the greatest proportion of the mammalian body.
M. RENNIE
The Physical Behaviour of Macromolecules with Biological Functions
S . P. SPRAGG
John Wiley and Sons,Chichester and New York, 1980,pp. 202.
f13.50
This is the first in a series of monographs on molecular
biophysics and biochemistry that is intended for graduate
students and other research workers. The macromolecules of the
title are predominantly proteins, although lipoproteins and
glycoproteins hardly feature at all, for reasons that are stated.
Physical behaviour is considered mainly in terms of hydrodynamic and related methods, with particular emphasis on the
insight that may be gained into the mutual interactions of the
macromolecules. A recurring theme is the necessity to deal with
a system as a complete entity, because biological activity is
generally associated with solvated molecules, and preferential
interaction of macromolecules with a particular constituent of
the solvent may have important repercussions.
This book is not intended primarily for those interested in the
minutiae of theory or experiment, although it incorporates basic
theory and references to relevant works that cover these matters.
Some might feel that the author’s rather unorthodox approach
makes a virtue of necessity by concentrating on the departures
from ideal behaviour that are so frequently manifest and the
opportunities they afford for learning about the interactions
responsible, especially if purely empirical relations can be
avoided.
The first chapter surveys the types of force operative between
molecules that determine conformation in a given environment
and thereby govern the biological activity. It is paradoxical that
so often the weaker forces, those most difficult to measure, play
a crucial role.
The second chapter deals with molecular-weight estimation
both by absolute methods and by relative methods that are
ultimately dependent on them. Although the resolution of the
comparative techniques is sometimes superior, it is often only at
the expense of the elimination of interactions that are of interest.
Next the general topic of shape is treated, and the behaviour
VOl. 9
of those molecules that can be usefully modelled as rigid
geometrical shapes is contrasted with the behaviour of those that
have a less well-defined configuration. The point is made that the
time-scale of the technique selected must be appropriate for the
type of molecule. Some readers may think that quasi-elastic
light-scattering receives more prominence than is merited by its
achievements to date, but the author feels there is justification in
its potential.
The final chapter covers systems in which associationdissociation undoubtedly occurs, as well as those which may be
regarded as merely non-ideal. Of course, there is a rather
indeterminate region between these categories. A distinction is
made between association that is of biological significance and
that which seems to be merely adventitious. Because multisubunit proteins are so numerous, this field is particularly
important, but the basic problem is that it is often difficult to
extract from limited experimental data the requisite parameters
needed to exclude or validate a particular model. Despite this,
qualitative conclusions that are worthwhile can sometimes be
reached.
Each chapter includes a section embodying its main conclusions. There are particularly useful sections in which
attention is drawn to the widely differing sensitivities of
experimental methods, and their errors are discussed quantitatively in regard to the limitations thay they may impose on the
conclusions that can be drawn. Many of the examples are
chosen from recent work, especially when earlier workers had
been unaware of the point under discussion.
The book is well produced and misprints are usually
inconsequential, occasionally amusing. The most notable absentee is the familiar Svedberg unit that is superseded by the
anonymous ps that is hardly widespread in the literature as yet.
This book forms an admirable start to the new series, and few
who have any interest in its subject matter could fail to find
something thought-provoking in it.
P. A. CHARLWOOD