Introduction to Enzyme and Coenzyme Chemistry - E-Library Home

Contents
vii
8 Enzymatic Addition/Elimination Reactions 193
8.1 Introduction 193
8.2 Hydratases and dehydratases 194
8.3 Ammonia lyases 199
8.4 Elimination of phosphate and pyrophosphate 202
8.5 CASE STUDY: 5-Enolpyruvyl-shikimate-3-phosphate (EPSP) synthase 204
9 Enzymatic Transformations of Amino Acids 210
9.1 Introduction 210
9.2 Pyridoxal 5 0 -phosphate-dependent reactions at the a-position
of amino acids 211
9.3 CASE STUDY: Aspartate aminotransferase 215
9.4 Reactions at b- and g-positions of amino acids 218
9.5 Serine hydroxymethyltransferase 220
9.6 N-Pyruvoyl-dependent amino acid decarboxylases 222
9.7 Imines and enamines in alkaloid biosynthesis 222
10 Isomerases 227
10.1 Introduction 227
10.2 Cofactor-independent racemases and epimerases 227
10.3 Keto–enol tautomerases 230
10.4 Allylic isomerases 231
10.5 CASE STUDY: Chorismate mutase 233
11 Radicals in Enzyme Catalysis 240
11.1 Introduction 240
11.2 Vitamin B 12 -dependent rearrangements 240
11.3 The involvement of protein radicals in enzyme catalysis 244
11.4 S-adenosyl methionine-dependent radical reactions 246
11.5 Biotin synthase and sulphur insertion reactions 249
11.6 Oxidised amino acid cofactors and quinoproteins 250
12 Non-Enzymatic Biological Catalysis 255
12.1 Introduction 255
12.2 Catalytic RNA 255
12.3 Catalytic antibodies 259
12.4 Synthetic enzyme models 265
Appendices 272
1. Cahn–Ingold–Prelog rule for stereochemical nomenclature 272
2. Amino acid abbreviations 274
3. A simple demonstration of enzyme catalysis 275
4. Answers to problems 277
Index 285