Enzyme Regulation in Metabolic Pathways

Enzyme Regulation in Metabolic Pathways shows the reader how to understand the roles of enzymes and their kinetic constants in intermediary metabolism. It provides a means of correlating data obtained in experimental studies to multiple possible mechanisms through which some enzyme may catalyze the conversion of a substrate to a product. Although not the most appropriate means of determining some potential kinetic mechanism, quasi-equilibrium assumptions are used throughout the book, keeping the rate equation derivations simple. Actual metabolic pathways with known (presumed) positive and negative regulation events are linked to these potential kinetic mechanisms using both rate equation derivations and data plots illustrating how the rate equation derivations can be used to explain the data plots.

This book will be a valuable reference for students in biological sciences and biochemistry majors required to take a core course in enzymology.

Preface vii

Author’s Review ix

Part I 1 Characteristics of Enzymes 3

2 Self-Assembly of Polymers 17

3 Beginnings of Equations 27

4 Metabolite Distribution Systems 37

5 Modification of Enzymatic Activity 51

6 Modification of Metabolite Flow Through Metabolic Pathways 67

7 Which is the Real Substrate? 75

8 Non-Quasi-Equilibrium Assumptions 79

9 Underlying Attributes of Assessing Enzymatic Activities 85

Part II 10 Breakdown of the Michaelis–Menten Equation (or Complex Enzyme Mechanisms) 97

11 Rate Equation Derivation by the King–Altman Method: Two Substrates and Two Products 117

12 Modification of Enzyme Mechanisms: The Next Generation 141

13 What Are These “Rate Constants” We Have Been Dealing With? 151

Index 165

Lloyd Wolfinbarger, Jr. Professor Emeritus at Old Dominion University in Norfolk, Virginia, USA

Enzymology is the study of enzymes as protein molecules, with specific folding patterns of the amino acid polymer and unique binding sites wherein intra- and inter-molecular distances define the specificity of the molecule to attract, bind to, and change some substrate molecule.

Enzyme Regulation in Metabolic Pathways shows the reader how to understand the roles of enzymes and their kinetic constants in intermediary metabolism. It provides a means of correlating data obtained in experimental studies to multiple possible mechanisms through which some enzyme may catalyze the conversion of a substrate to a product. Quasi-equilibrium assumptions are used throughout the book, keeping the rate equation derivations simple. Actual metabolic pathways with known (presumed) positive and negative regulation events are linked to these potential kinetic mechanisms using both rate equation derivations and data plots illustrating how the rate equation derivations can be used to explain the data plots.

This book will be a valuable reference for students in biological sciences and biochemistry, taking a core course in enzymology.