CONTENTS A note on units ... xv List of abbreviations ... xvii 1 Introduction ... 1 1.1 Aims of the book ... 1 1.2 Historical aspects ... 1 1.3 Remarkable properties of enzymes as catalysts ... 3 1.4 Cofactors ... 8 1.5 Nomenclature and classification of enzymes ... 10 1.6 The contents of this book ... 14 References ... 15 2 The purification of enzymes ... 17 2.1 Introduction ... 17 2.2 Why isolate enzymes? ... 17 2.3 Objectives and strategy in enzyme purification ... 17 2.4 Choice of source ... 19 2.5 Methods of homogenization ... 20 2.6 Methods of separation ... 21 2.7 How to judge the success of a purification procedure ... 35 2.8 Examples of purification procedures ... 38 2.9 Conclusions from the examples of enzyme purification ... 51 References ... 52 3 The structure of enzymes ... 56 3.1 Introduction ... 56 3.2 The determination of Mr ... 57 3.3 The determination of amino-acid composition ... 63 3.4 The determination of primary structure ... 72 3.5 The determination of secondary and tertiary structure ... 95 3.6 The determination of quaternary structure ... 117 3.7 The unfolding and refolding of enzymes ... 125 3.8 Concluding remarks ... 128 References ... 129 4 An introduction to enzyme kinetics ... 136 4.1 Outline of the chapter ... 137 4.2 How do we obtain kinetic data? ... 139 4.3 How do we analyse kinetic data? ... 139 4.4 Pre-steady-state kinetics ... 169 4.5 Concluding remarks ... 173 References ... 173 Appendix 4.1 ... 176 Appendix 4.2 ... 177 Appendix 4.3 ... 179 References for Appendices ... 180 5 The mechanism of enzyme action ... 181 5.1 Introduction ... 181 5.2 Definition of the mechanism of an enzyme-catalysed reaction ... 181 5.3 Background to catalysis ... 182 5.4 Experimental approaches to the determination of enzyme mechanisms ... 190 5.5 Examples of enzyme mechanisms ... 205 5.6 Concluding comments on enzyme mechanisms ... 205 References ... 247 6 The control of enzyme activity ... 253 6.1 Introduction ... 253 6.2 Control of the activities of single enzymes ... 253 6.3 Control of metabolic pathways ... 278 6.4 Examples of control of metabolic pathways ... 289 6.5 Concluding remarks ... 307 References ... 308 Appendix 6.1 ... 312 7 Enzymes in organized systems ... 315 7.1 Introduction ... 315 7.2 Organized enzyme systems ... 315 7.3 RNA nucleotidyltransferase from E. coli ... 316 7.4 The occurrence and isolation of multienzyme proteins ... 321 7.5 Phylogenetic distribution of multienzyme proteins ... 323 7.6 Properties of multienzyme proteins ... 323 7.7 The pyruvate dehydrogenase system ... 324 7.8 Oxoglutarate dehydrogenase and branched chain 2-oxo acid dehydrogenase multienzyme complexes ... 332 7.9 The tryptophan synthase multienzyme complex from E. coli ... 333 7.10 Carbamoyl phosphate synthase and the associated enzymes of the pyrimidine and arginine biosynthetic pathways in E. coli, fungi, and mammalian cells ... 339 7.11 Multienzyme polypeptides: aspartate kinase-homoserine dehydrogenase, fatty-acid synthase, and the arom complex ... 344 7.12 The glycogen particle ... 357 7.13 DNA synthesis ... 359 7.14 Conclusions ... 360 References ... 360 8 Enzymes in the cell ... 365 8.1 Introduction ... 365 8.2 Intracellular compartmentation ... 366 8.3 Compartmentation of metabolic pathways ... 378 8.4 Vectorial organization of enzymes associated with membranes ... 395 8.5 The concentrations of enzymes and substrates in vivo ... 405 8.6 Conclusions ... 417 References ... 418 9 Enzyme turnover ... 423 9.1 Introduction ... 423 9.2 Mechanism of enzyme synthesis ... 424 9.3 Kinetics of enzyme turnover ... 426 9.4 Methods for measurement of rates of enzyme turnover ... 428 9.5 Results from measurements of rates of enzyme turnover ... 431 9.6 Possible correlations between the rates of turnover and the structure and function of enzymes ... 433 9.7 The mechanisms of protein degradation ... 436 9.8 The significance of enzyme turnover ... 440 9.9 Conclusions ... 446 References ... 446 Appendix 9.1 ... 449 10 Clinical aspects of enzymology ... 450 10.1 Introduction ... 450 10.2 Determination of enzyme activities for clinical diagnosis ... 450 10.3 Clinical enzymology of liver disease ... 454 10.4 Clinical enzymology of heart disease ... 455 10.5 Other enzyme activities that become elevated in serum in disease ... 457 10.6 The detection and significance of enzyme deficiencies ... 460 10.7 The use of enzymes to determine the concentrations of metabolites of clinical importance ... 465 10.8 Enzyme therapy ... 473 10.9 Conclusions ... 476 References ... 476 11 Enzyme technology ... 478 11.1 Introduction ... 478 11.2 Use of microorganisms in brewing and cheesemaking ... 478 11.3 Use of microorganisms in the production of organic chemicals ... 481 11.4 Use of isolated enzymes in industrial processes ... 481 11.5 Immobilized enzymes ... 488 References ... 497 Appendix: Enzymes referred to in Chapters 1-11 ... 499 Index ... 516