Introduction to Enzyme and Coenzyme Chemistry - E-Library Home

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All Enzymes are Proteins 9 General structure (side chain R) + H 3 N H R CO 2 − Aliphatic H -CH 3 Glycine (Gly, G) Alanine (Ala, A) CH 3 CH CH 3 Valine (Val, V) Methionine (Met, M) CH CH 3 Leucine (Leu, L) H 2 N + CO 2 − Proline (Pro, P) CH 2 CH 2 CH 3 H CH 3 CH 3 Isoleucine (Ile, I) Acidic -CH 2 -CO 2 H -CH 2 -CH 2 -CO 2 H Aspartate (Asp, D) Glutamate (Glu, E) Basic -CH 2 -CH 2 -S-CH 3 Tryptophan (Trp, W) -CH 2 -CH 2 -CH 2 -CH 2 -NH 2 -CH 2 -CH 2 -CH 2 -NH NH Lysine (Lys, K) Arginine (Arg, R) CH 2 N NH Histidine (His, H) NH 2 Polar -CH 2 -OH Serine (Ser, S) H OH Threonine (Thr, T) -CH 2 -SH Cysteine (Cys, C) CH 3 -CH 2 -CONH 2 Asparagine (Asn, N) -CH 2 -CH 2 -CONH 2 Glutamine (Gln, Q) Aromatic CH 2 CH 2 Phenylalanine (Phe, F) CH 2 OH Tyrosine (Tyr, Y) Figure 2.2 The side chains of the 20 a-amino acids found in proteins. Whole amino acid structure shown for proline. Functionally important groups highlighted in red. N H side chains of phenylalanine (Phe) and tryptophan (Trp). The remainder of the amino acid side chains are hydrophilic (‘water-loving’) in character. Aspartic acid (Asp) and glutamic acid (Glu) contain carboxylic acid side chains, and their corresponding primary amides are found as asparagine (Asn) and glutamine
10 Chapter 2 (Gln). There are three basic side chains consisting of the e-amino group of lysine (Lys), the guanidine group of arginine (Arg), and the imidazole ring of histidine (His). The polar nucleophilic side chains that will assume a key role in enzyme catalysis are the primary hydroxyl of serine (Ser), the secondary hydroxyl of threonine (Thr), the phenolic hydroxyl group of tyrosine (Tyr) and the thiol group of cysteine (Cys). The nature of the side chain confers certain physical and chemical properties upon the corresponding amino acid, and upon the polypeptide chain in which it is located. The amino acid side chains are therefore of considerable structural importance and, as we shall see in Chapter 3, they play key roles in the catalytic function of enzymes. 2.3 The primary structure of polypeptides To form the polypeptide chain found in proteins each amino acid is linked to the next via an amide bond, forming a linear sequence of 100–1000 amino acids – this is the primary structure of the protein. A portion of the amino-terminal (or N-terminal) end of a polypeptide is shown in Figure 2.3, together with the abbreviated representations for this peptide sequence. The sequence of amino acids in the polypeptide chain is all-important. It contains all the information to confer both the three-dimensional structure of proteins in general and the catalytic activity of enzymes in particular. How is this amino acid sequence controlled It is speciWed by the nucleotide sequence of the corresponding gene, the piece of DNA (deoxyribonucleic acid) which encodes for that particular protein in that particular organism. To give an idea of how this is achieved, I will give a simpliWed account of how the polypeptide sequence is derived from the gene sequence. For a more detailed description the reader is referred to biochemical textbooks. Genes are composed of four deoxyribonucleotides (or ‘bases’): deoxyadenine (dA), deoxycytidine (dC), deoxyguanine (dG) and deoxythymidine (dT), + H 3 N H O SCH 3 H N O H CH 3 N H H O H N H O OH H N H CO 2 − O H N Met - Ala - Phe - Ser - Asp - M A F S D Figure 2.3 Structure of the N-terminal portion of a polypeptide chain.
Page 1 and 2: Introduction to Enzyme and Coenzyme
Page 4 and 5: Introduction to Enzyme and Coenzyme
Page 6 and 7: Contents Preface Representation of
Page 8: Contents vii 8 Enzymatic Addition/E
Page 11 and 12: Representation of Protein Three-Dim
Page 13 and 14: 2 Chapter 1 H 2 N O NH 2 + H 2 O Ja
Page 15 and 16: 4 Chapter 1 Table 1.1 The vitamins.
Page 17 and 18: 6 Chapter 1 has very diVerent biolo
Page 19: 2 All Enzymes are Proteins 2.1 Intr
Page 23 and 24: 12 Chapter 2 AAA Lys ACA Thr AGA Ar
Page 25 and 26: 14 Chapter 2 H N O H N O Figure 2.8
Page 27 and 28: 16 Chapter 2 (a) (b) Figure 2.12 St
Page 29 and 30: 18 Chapter 2 Figure 2.14 Structure
Page 31 and 32: 20 Chapter 2 (a) X Y Enzyme + Subst
Page 33 and 34: 22 Chapter 2 maintaining protein te
Page 35 and 36: 24 Chapter 2 surface glycoprotein g
Page 37 and 38: 26 Chapter 2 O-linked glycosylation
Page 39 and 40: 28 Chapter 2 Metalloproteins I. Ber
Page 41 and 42: 30 Chapter 3 O N H R CO 2 H acylase
Page 43 and 44: 32 Chapter 3 (a) Free energy uncata
Page 45 and 46: 34 Chapter 3 Ester k rel Effective
Page 47 and 48: 36 Chapter 3 3.4 The importance of
Page 49 and 50: 38 Chapter 3 pKa Tyrosine CH 2 O H
Page 51 and 52: 40 Chapter 3 glycoside hydrolysis (
Page 53 and 54: 42 Chapter 3 O O Glu 143 O − R H
Page 55 and 56: 44 Chapter 3 the hydroxyl groups of
Page 57 and 58: 46 Chapter 3 E + S E + S ES' ES ‘
Page 59 and 60: 48 Chapter 3 Examination of protein
Page 61 and 62: 50 Chapter 3 (Note: Similar results
Page 63 and 64: 52 Chapter 4 (1) Direct UV (2) Radi
Page 65 and 66: 54 Chapter 4 Figure 4.3 PuriWcation
Page 67 and 68: 56 Chapter 4 The two kinetic consta
Page 69 and 70: 58 Chapter 4 Lineweaver−Burk Plot
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60 Chapter 4 E + S K i EI+ I ES E +
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62 Chapter 4 (2) by treatment with
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64 Chapter 4 In general the stereoc
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H D T CO 2 H CO − 2 T HO D H −
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68 Chapter 4 4.5 The existence of i
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70 Chapter 4 18O 18O 18 O O P O −
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72 Chapter 4 If a reaction involves
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74 Chapter 4 O D H ketosteroid isom
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76 Chapter 4 Table 4.3 Group speciW
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78 Chapter 4 [S] (mM) Rate of produ
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80 Chapter 4 Enzyme kinetics I.H. S
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82 Chapter 5 O = C NHR peptidase H
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84 Chapter 5 non-speciWc protease c
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86 Chapter 5 His 57 His 57 Asp 102
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88 Chapter 5 Other serine proteases
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90 Chapter 5 Figure 5.8 Structure o
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92 Chapter 5 now predominate Perhap
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OH R O Zn 2+ O O O Ph Glu 270 H 2 N
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96 Chapter 5 CASE STUDY: HIV-1 prot
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98 Chapter 5 HO Transition state pe
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100 Chapter 5 The aminoacyl group o
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102 Chapter 5 5.5 Enzymatic phospho
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104 Chapter 5 Figure 5.29 Structure
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Page 119 and 120:
108 Chapter 5 Adenosine 5 0 -tripho
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110 Chapter 5 functional group. Gly
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112 Chapter 5 CH 2 OH O RO HO OH O
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114 Chapter 5 to these atoms that t
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116 Chapter 5 Problems (1) Using pa
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118 Chapter 5 (6) Retaining glycosi
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120 Chapter 5 J.R. Knowles (1980) E
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122 Chapter 6 +1.0 Redox potential
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Table 6.1 Classes of redox enzymes.
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126 Chapter 6 An important point is
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128 Chapter 6 O H − OH − O OH H
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130 Chapter 6 one-electron transfer
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132 Chapter 6 (a) R N H + N O R N H
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134 Chapter 6 Inactivation by trany
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Page 149 and 150:
138 Chapter 6 (a) (b) Figure 6.23 S
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140 Chapter 6 glutathione called tr
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142 Chapter 6 neither has a stable
Page 155 and 156:
144 Chapter 6 of the haem cofactor
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146 Chapter 6 Figure 6.33 Active si
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148 Chapter 6 HO H N N O O H N prol
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150 Chapter 6 R R R O 2 , Fe 2+ O O
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152 Chapter 6 CoA. Explain these re
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154 Chapter 6 NADH models O. Almars
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7 Enzymatic Carbon-Carbon Bond Form
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158 Chapter 7 O H − OH O − O H
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Page 173 and 174:
162 Chapter 7 Figure 7.6 Active sit
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164 Chapter 7 7.3 Claisen enzymes I
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166 Chapter 7 CoAS O EnzB − H D T
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168 Chapter 7 onto the acetyl-thioe
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170 Chapter 7 In the case of erythr
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172 Chapter 7 O HO O − O ATP ADP
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174 Chapter 7 CO 2 − vitamin K-de
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176 Chapter 7 7.8 Thiamine pyrophos
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178 Chapter 7 HN N + N H NH S O OPP
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180 Chapter 7 O OH OH camphor geran
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182 Chapter 7 CH 3 * OPP (−)pinen
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Page 197 and 198:
186 Chapter 7 C C C C C O OCH 3 C H
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188 Chapter 7 AcO HO HO NHAc O OH +
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190 Chapter 7 (9) Usnic acid is a n
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192 Chapter 7 Radical couplings W.M
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194 Chapter 8 C-O cleavage H E1 H C
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196 Chapter 8 leads to the formatio
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198 Chapter 8 aconitase citrate cis
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200 Chapter 8 *H R H H CO 2 − NH
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202 Chapter 8 EnzB − 2 H − O 2
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204 Chapter 8 involves no change in
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206 Chapter 8 Glyphosate H H N CO
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208 Chapter 8 (5) Chorismic acid (s
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9 Enzymatic Transformations of Amin
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CO − − 2 CO 2 H H CO 2 − N +
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214 Chapter 9 - BEnz CO − 2 Cl H
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216 Chapter 9 Arg 292 Arg 292 Lys 2
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218 Chapter 9 Arg 292 Asp 292 HN H
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220 Chapter 9 S − B 1 Enz H − C
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222 Chapter 9 9.6 N-Pyruvoyl-depend
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224 Chapter 9 The biosyntheses of n
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226 Chapter 9 Further reading Gener
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228 Chapter 10 B 1 - H + NH 3 CO
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230 Chapter 10 ‘low-barrier’ +
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232 Chapter 10 H S C 6 H 13 HN His
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234 Chapter 10 O H NH 3 CO 2 − CO
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236 Chapter 10 sub-units. Each sub-
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238 Chapter 10 Further reading Gene
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11 Radicals in Enzyme Catalysis 11.
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242 Chapter 11 CH 2 Co III Ad H OH
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244 Chapter 11 − O 2 C − O CO
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246 Chapter 11 H N H O 734 H N H PF
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248 Chapter 11 H H* + H + H 3 N CO
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250 Chapter 11 O HN NH + H 3 N H 3
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252 Chapter 11 cofactor is involved
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254 Chapter 11 Protein Radicals J.
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256 Chapter 12 self-splicing reacti
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258 Chapter 12 Figure 12.2 Structur
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260 Chapter 12 antigen combining si
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262 Chapter 12 R O OR' OH − R O
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264 Chapter 12 CO 2 − − O 2 C O
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266 Chapter 12 (1) Selective substr
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268 Chapter 12 HO O HO OH HO OH O O
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270 Chapter 12 Problems (1) How rev
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Appendix 1: Cahn-Ingold-Prelog Rule
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Appendix 2: Amino Acid Abbreviation
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276 Appendix 3 Preparation of orang
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278 Appendix 4 (2) Intramolecular a
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280 Appendix 4 from water at a-posi
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282 Appendix 4 Chapter 8 (1) Treat
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284 Appendix 4 (b) Formation of rad
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286 Index b-hydroxydecanoyl thioest
Page 299 and 300:
288 Index glycosylation 26-7 glysop
Page 301 and 302:
290 Index phenylalanine ammonia lya
Page 303:
292 Index transition states 31-2 an
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