Fundamentals of Enzyme Kinetics

Athel Cornish-Bowden

• Publisher: Wiley-Blackwell
• Year: 2013
• ISBN:
  9783527665495
• Edition: 4
• Topic: Sciences biologiques
• Subtopic: Biotechnologie

Now in its fourth edition, this textbook is one of the few titles worldwide to cover enzyme kinetics in its entire scope and the only one to include its implications for bioinformatics and systems biology. Multi-enzyme complexes and cooperativity are therefore treated in more detail than in any other textbook on the market.
The respected and well known author is one of the most experienced researchers into the topic and writes with outstanding style and didactic clarity. As with the previous editions, he presents here steady-state kinetics and fast reactions, supplementing each chapter with problems and solutions. For the first time, this edition features a companion website providing all figures in colour
www.wiley-vch.de/home/fundenzykinet

Chapter 1
Basic Principles of Chemical Kinetics

1.1 Symbols, terminology and abbreviations

This book follows as far as possible the recommendations of the International Union of Biochemistry and Molecular Biology. However, as these allow some latitude and in any case do not cover all of the cases that we shall need, it is useful to begin by noting some points that apply generally in the book. First of all, it is important to recognize that a chemical substance and its concentration are two different entities and need to be represented by different symbols. The recommendations allow square brackets around the chemical name to be used without definition for its concentration, so [glucose] is the concentration of glucose, [A] is the concentration of a substance A, and so on. In this book I shall use this convention for names that consist of more than a single letter, but it has the disadvantage that the profusion of square brackets can lead to forbiddingly complicated equations in enzyme kinetics (see some of the equations in Chapter 8, for example, and imagine how they would look with square brackets). Two simple alternatives are possible: one is just to put the name in italics, so the concentration of A is A, for example, and this accords well with the standard convention that chemical names are written in roman (upright) type and algebraic symbols are written in italics. However, experience shows that many readers barely notice whether a particular symbol is roman or italic, and so it discriminates less well than one would hope between the two kinds of entity. For this reason I shall use the lower-case italic letter that corresponds to the symbol for the chemical entity, so a is the concentration of A, for example. If the chemical symbol has any subscripts, these apply unchanged to the concentration symbol, so a₀ is the concentration of A₀, for example. Both of these systems (and others) are permitted by the recommendations as long as each symbol is defined when first used. This provision is satisfied in this book, and it is good to follow it in general, because almost nothing that authors consider obvious is perceived as obvious by all their readers. In the problems at the ends of the chapters, incidentally, the symbols may not be the same as those used in the corresponding chapters: this is intentional, because in the real world one cannot always expect the questions that one has to answer to be presented in familiar terms.

Chapter 8, pages 189–226

As we shall see, an enzyme-catalyzed reaction virtually always consists of two or more steps, and as we shall need symbols to refer to the different steps it is necessary to have some convenient indexing system to show which symbol refers to which step. The recommendations do not impose any particular system, but, most important, they do require the system in use to be stated. Because of the different ways in which, for example, the symbol k₂ has been used in the biochemical literature one should never assume in the absence of a clear definition what is intended. In this book I use the system preferred by the recommendations: for a reaction of n steps, these are numbered 1, 2 … n; lower-case italic k with a positive subscript refers to the kinetic properties of the forward step corresponding to the subscript, for example, k₂ refers to the forward direction of the second step; the same with a negative subscript refers to the corresponding reverse reaction, for example, k₋₂ for the second step; a capital italic K with a subscript refers to the thermodynamic (equilibrium) properties of the whole step and is typically the ratio of the two kinetic constants, for example, K₂ = k₂/k₋₂.

The polic...