Mass of Amino Acid residues
The mass of a residue is the mass of the amino acid less 18,i.e. the mass of the molecule of H2O which is loss after the formation of the peptide bond. Adapted from: Biemann, K. (1990) in Methods in Enzymology (McCloskey, J. A., Ed.), Vol. 193, pp. 888 (Academic Press, San Diego).
Amino acid 3-ltr 1-ltr Residue mass code code Monoisotopic Average Glycine Gly G 57.02147 57.052 Alanine Ala A 71.03712 71.079 Serine Ser S 87.03203 87.078 Proline Pro P 97.05277 97.117 Valine Val V 99.06842 99.133 Threonine Thr T 101.04768 101.105 Cysteine Cys C 103.00919 103.144 Isoleucine Ile I 113.08407 113.160 Leucine Leu L 113.08407 113.160 Asparagine Asn N 114.04293 114.104 Aspartic acid Asp D 115.02695 115.089 Glutamine Gln Q 128.05858 128.131 Lysine Lys K 128.09497 128.174 Glutamic acid Glu E 129.04260 129.116 Methionine Met M 131.04049 131.198 Histidine His H 137.05891 137.142 Phenylalanine Phe F 147.06842 147.177 Arginine Arg R 156.10112 156.188 Tyrosine Tyr Y 163.06333 163.170 Tryptophan Trp W 186.07932 186.213 Homoserine Hse 101.04768 101.105 Homoserine lactone Hsl 83.03712 83.090 Pyroglutamic acid Glp 111.03203 111.100 Carbamidomethylcysteine 160.03065 160.197 Carboxymethylcysteine 161.01466 161.181 Pyridylethylcysteine 208.06703 208.284 Mass differences due to amino acid modifications -79 dephospho -58 Desmosine (from Lysine) -48 decomposed carboxymethylated Methionine -43 gamma-glutamyl semialdehyde (from arginine) -42 Ornithine (from Arginine) -34 Lysinoalanine (from Cysteine) -34 Lanthionine (from Cysteine) -34 Dehydroalanine (from Cysteine) -30 Homoserine formed from Met by CNBr treatment -18 Dehydration (-H2O) -18 S-gamma-Glutamyl (crosslinked to Cysteine) -18 O-gamma-Glutamyl- (Crosslink to Serine) -18 Serine to Dehydroalanine -18 Alaninohistidine (Serine crosslinked to theta or pi carbon of Histidine) -18 Succinimide formation from aspartic acid -17 Succinimide formation from asparagine -17 Pyroglutamic Acid formed from Gln -17 N-pyrrolidone carboxyl (N terminus) -17 N alpha -(gamma-Glutamyl)-lysine -17 N-(beta-Aspartyl)-Lysine (Crosslink) -16 Pyruvoyl- (Serine) -4 3,3',5,5'-TerTyr (Crosslink) -2 Disulphide bond formation (Cystine) -2 S-(2-Histidyl)- (Crosslinked to Cysteine) -2 S-(3-Tyr) (Crosslinked to Cysteine) -2 3,3'-BiTyr (Crosslink) -2 IsodiTyr (Crosslink) -1 Allysine (from Lysine) -1 Amide formation (C terminus) 1 Deamidation of Asparagine and Glutamine to Aspartate and Glutamate 1 Citruline (from Arginine) 13 Syndesine (from Lysine) 14 Methylation (N terminus, N epsilon of Lysine, O of Serine, Threonine or C terminus, N of Asparagine) 15 delta-Hydroxy-allysine (from Lysine) 16 Oxohistidine (from histidine) 16 Hydroxylation (of delta C of Lysine, beta C of Tryptophan, C3 or C4 of Proline, beta C of Aspartate) 16 Oxidation of Methionine (to Sulphoxide) 16 Sulfenic Acid (from Cysteine) 16 3,4-Dihydroxy-Phenylalanine (from Tyrosine) (DOPA) 22 Sodium 28 Ethyl 28 N,N dimethylation (of Arginine or Lysine) 28 2,4-BisTrp-6,7-dione (from Tryptophan) 28 Formylation (CHO) 30 6,7 Dione (from Tryptophan) 32 3,4,6-Trihydroxy-Phenylalanine (from Tyrosine) (TOPA) 32 3,4-Dihydroxylation (of Proline) 32 Oxidation of Methionine (to Sulphone) 34 3-Chlorination (of Tyrosine with 35Cl) 36 3-Chlorination (of Tyrosine with 37Cl) 38 Potassium 41 Carbamylation 42 Acetylation (N terminus, N epsilon of Lysine, O of Serine) (Ac) 43 N-Trimethylation (of Lysine) 44 gamma Carboxylation of Glutamate or beta Carboxylation of Aspartate 44 disodium 45 Nitro (NO2) 46 beta-Methylthio-aspartic acid 56 t-butyl ester(OtBu) and t-butyl (tBu) 57 Glycyl (-G-,-Gly-) 58 Carboxymethyl (on Cystine) 60 sodium + potassium 64 Selenocysteine (from Serine) 68 3,5-Dichlorination (of Tyrosine with 35Cl) 69 Dehydroalanine (Dha) 70 3,5-Dichlorination (of Tyrosine with mixture of 35Cl and 37Cl)) 70 Pyruvate 71 Acrylamidyl or Acrylamide adduct 71 Sarcosyl 71 Alanyl (-A-, -Ala-) 71 Acetamidomethyl (Acm) 72 3,5-Dichlorination (of Tyrosine with 37Cl) 74 S-(sn-1-Glyceryl) (on Cysteine) 74 Glycerol Ester (on Glutamic acid side chain) 75 Glycine (G, Gly) 76 Beta mercaptoethanol adduct 76 Phenyl ester (OPh) (on acidic) 78 3-Bromination (of Tyrosine with 79Br) 80 Phosphorylation (O of Serine, Threonine, Tyrosine and Aspartate, N epsilon of Lysine) 80 3-Bromination (of Tyrosine with 81Br) 80 Sulphonation (SO3H) (of PMC group) 80 Sulphation (of O of Tyrosine) 82 Cyclohexyl ester (OcHex) 83 Homoseryl lactone 83 Dehydroamino butyric acid (Dhb) 85 Gamma Aminobutyryl 85 2-Aminobutyric acid (Abu) 85 2-Aminoisobutyric acid (Aib) 86 Diaminopropionyl 86 t-butyloxymethyl (Bum) 87 N-(4-NH2-2-OH-butyl)- (of Lysine) (Hypusine) 87 Seryl (-S-, -Ser-) 88 t-butylsulfenyl (StBu) 89 Alanine (A, Ala) 89 Sarcosine (Sar) 90 Anisyl 90 Benzyl (Bzl) and benzly ester (OBzl) 93 1,2-ethanedithiol (EDT) 95 Dehydroprolyl 96 Trifluoroacetyl (TFA) 97 N-hydroxysuccinimide (ONSu, OSu) 97 Prolyl (-P-, -Pro-) 99 Valyl (-V-, -Val-) 99 Isovalyl (-I-,-Iva-) 100 t-Butyloxycarbonyl (tBoc) 101 Threoyl (-T-, -Thr-) 101 Homoseryl (-Hse-) 103 Cystyl (-C-, -Cys-) 104 Benzoyl (Bz) 104 4-Methylbenzyl (Meb) 105 Serine (S, Ser) 106 HMP (hydroxymethylphenyl) linker 106 Thioanisyl 106 Thiocresyl 107 Diphthamide (from Histidine) 111 Pyroglutamyl 111 2-Piperidinecarboxylic acid (Pip) 113 Hydroxyprolyl (-Hyp-) 113 Norleucyl (-Nle-) 113 Isoleucyl (-I-, -Ile-) 113 Leucyl (-L-, -Leu-) 114 Ornithyl (-Orn-) 114 Asparagyl (-N-, -Asn-) 114 t-amyloxycarbonyl (Aoc) 115 Proline (P, Pro) 115 Aspartyl (-D-, -Asp-) 117 Succinyl 117 Valine (V, Val) 117 Hydroxybenzotriazole ester (HOBt) 118 Dimethylbenzyl (diMeBzl) 119 Threonine (T, Thr) 119 Cysteinylation 120 Benzyloxymethyl (Bom) 120 p-methoxybenzyl (Mob, Mbzl) 121 4-Nitrophenyl, p-Nitrophenyl (ONp) 121 Cysteine (C, Cys) 125 Chlorobenzyl (ClBzl) 126 Iodination (of Histidine[C4] or Tyrosine[C3]) 128 Glutamyl (-Q-, -Gln-) 128 N-methyl Lysyl 128 Lysyl (-K-, -Lys-) 129 O-Methyl Aspartamyl 129 Glutamyl (-E-, -Glu-) 130 N alpha -(gamma-Glutamyl)-Glu 131 Norleucine (Nle) 131 Hydroxy Aspartamyl 131 Hydroxyproline (Hyp) 131 bb-dimethyl Cystenyl 131 Isoleucine (I, Ile) 131 Leucine (L, Leu) 131 Methionyl (-M-, -Met-) 132 Asparagine (N, Asn) 132 Pentoses (Ara, Rib, Xyl) 133 Aspartic Acid (D, Asp) 134 Dmob (Dimethoxybenzyl) 134 Benzyloxycarbonyl (Z) 134 Adamantyl (Ada) 135 p-Nitrobenzyl ester (ONb) 137 Histidyl (-H-, -His-) 142 N-methyl Glutamyl 143 O-methyl Glutamyl 144 Hydroxy Lysyl (-Hyl-) 145 Methyl Methionyl 146 Glutamine (Q, Gln) 146 Aminoethyl Cystenyl 146 Pentosyl 146 Deoxyhexoses (Fuc, Rha) 146 Lysine (K, Lys) 146 Aminoethyl cystenyl (-AECys-) 147 4-Glycosyloxy- (pentosyl,C5) (of Proline) 147 Methionyl Sulfoxide 147 Glutamic Acid (E, Glu) 147 Phenylalanyl- (-F-, -Phe-) 148 Pyridyl Alanyl 149 Fluorophenylalanyl 149 2-Nitrobenzoyl (NBz) 149 Methionine (M, Met) 151 3-methyl Histidyl 153 2-Nitrophenylsulphenyl (Nps) 154 4-Toluenesulphonyl (Tosyl, Tos) 154 3-nitro-2-pyridinesulfenyl (Npys) 155 Histidine (H, His) 156 3,5-Dibromination (of Tyrosine with 79Br) 156 Arginyl (-R-, -Arg-) 157 Citrulline 158 3,5-Dibromination (of Tyrosine with mixture of 79Br and 81Br) 159 Dichlorobenzyl (Dcb) 160 3,5-Dibromination (of Tyrosine with 81Br) 160 Carboxyamidomethyl Cystenyl 161 Carboxymethyl Cystenyl 161 Methylphenylalanyl 161 Hexosamines (GalN, GlcN) 161 Carboxymethyl cysteine (Cmc) 162 N-Glucosyl (N terminus or N epsilon of Lysine) (Aminoketose) 162 O-Glycosyl- (to Serine or Threonine) 162 Hexoses (Fru, Gal, Glc, Man) 162 Inositol 163 MethionylSulphone 163 Tyrosinyl (-Y-, -Tyr-) 165 Phenylalanine (F, Phe) 166 2,4 -dinitrophenyl (Dnp) 166 Pentaflourophenyl (Pfp) 166 Diphenylmethyl (Dpm) 167 Phospho Seryl 169 2-Chlorobenzyloxycarbonyl (ClZ) 169 Napthyl acetyl 170 Isopropyl Lysyl 170 N-methyl Arginyl 172 Ethaneditohiol/TFA cyclic adduct 173 Carboxy Glutamyl (Gla) 174 Acetamidomethyl Cystenyl 174 Acrylamidyl Cystenyl 174 Arginine (R, Arg) 176 N-Glucuronyl (N terminus) 177 delta-Glycosyloxy- (of Lysine) or beta-Glycosyloxy- (of Phenylalanine or Tyrosine) 177 4-Glycosyloxy- (hexosyl,C6) (of Proline) 177 Benzyl Seryl 177 N-methyl Tyrosinyl 179 p-Nitrobenzyloxycarbonyl (4Nz) 179 2,4,5-Trichlorophenyl 180 2,4,6-trimethyloxybenzyl (Tmob) 180 Xanthyl (Xan) 181 Phospho Threonyl 181 Tyrosine (Y, Tyr) 182 Chlorophenylalanyl 182 Mesitylene-2-sulfonyl (Mts) 186 Carboxymethyl Lysyl 186 Tryptophanyl (-W-, - Trp-) 188 N-Lipoyl- (on Lysine) 190 Matrix alpha cyano MH+ 191 Benzyl Threonyl 193 Benzyl Cystenyl 197 Napthyl Alanyl 198 Succinyl Aspartamyl 200 Succinimidophenyl carb.. 201 HMP (hydroxymethylphenyl)/TFA adduct 203 N-acetylhexosamines (GalNAc, GlcNAc) 204 Tryptophan (W, Trp) 204 Cystine ((Cys)2) 204 Farnesylation 206 S-Farnesyl- 208 Myristoleylation (myristoyl with one double bond) 208 Pyridylethyl Cystenyl 210 Myristoylation 212 4-Methoxy-2,3,6-trimethylbenzenesulfonyl (Mtr) 213 2-Bromobenzyloxycarbonyl (BrZ) 214 Formyl Tryptophanyl 219 Benzyl Glutamyl 219 Anisole Adducted Glutamyl 222 S-cystenyl Cystenyl 222 9-Fluorenylmethyloxycarbonyl (Fmoc) 226 Biotinylation (amide bond to lysine) 226 Dimethoxybenzhydryl (Mbh) 229 N-Pyridoxyl (on Lysine) 231 Pyridoxal phosphate (Schiff Base formed to lysine) 233 Nicotinyl Lysyl 233 Dansyl (Dns) 238 2-(p-biphenyl)isopropyl-oxycarbonyl (Bpoc) 238 Palmitoylation 242 "Triphenylmethyl (Trityl, Trt)" 243 Tyrosinyl Sulphate 243 Phospho Tyrosinyl 252 Pbf (pentamethyldihydrobenzofuransulfonyl) 252 3,5-Diiodination (of Tyrosine) 258 3,5-di-I" 259 N alpha -(gamma-Glutamyl)-Glu2 266 O-GlcNAc-1-phosphorylation (of Serine) 266 "2,2,5,7,8- Pentamethylchroman-6-sulphonyl (Pmc)" 266 Stearoylation 272 Geranylgeranylation 276 S-Geranylgeranyl 289 5'phos dCytidinyl 289 iodo Tyrosinyl 290 Aldohexosyl Lysyl 291 Sialyl 291 N-acetylneuraminic acid (Sialic acid, NeuAc, NANA, SA) 304 5'phos dThymidinyl 305 5'phos Cytidinyl 305 Glutathionation 306 O-Uridinylylation (of Tyrosine) 306 5'phos Uridinyl 307 S-farnesyl Cystenyl 307 N-glycolneuraminic acid (NeuGc) 313 5'phos dAdenosyl 324 O-pantetheinephosphorylation (of Serine) 327 SucPhencarb Lysyl 329 5'phos dGuanosyl 329 5'phos Adenosinyl 329 O-5'-Adenosylation ( of Tyrosine) 339 4'-Phosphopantetheine 341 GL2 342 S-palmityl Cystenyl 345 5'phos Guanosyl 354 Biotinyl Lysyl 365 Hex-HexNAc 388 N alpha -(gamma-Glutamyl)-Glu3 391 Dioctyl Phthalate 395 PMC Lysyl 409 Aedans Cystenyl 413 Dioctyl Phthalate Sodium Adduct 415 di-iodo Tyrosinyl 423 PMC Arginyl 454 S-Coenzyme A 457 AMP Lysyl 470 3,5,3'-Triiodothyronine (from Tyrosine) 524 S-(sn-1-Dipalmitoyl-glyceryl)- (on Cysteine) 541 S-(ADP-ribosyl)- (on Cysteine) 541 N-(ADP-ribosyl)- (on Arginine) 541 O-ADP-ribosylation (on Glutamate or C terminus) 541 ADP-rybosylation (from NAD) 587 S-Phycocyanobilin (on Cysteine) 617 S-Heme (on Cysteine) 648 N theta -(ADP-ribosyl) diphthamide (of Histidine) 657 NeuAc-Hex-HexNAc 775 MGDG 783 O-8 alpha-Flavin [FAD])- (of Tyrosine) 784 S-(6-Flavin [FAD])- (on Cysteine) 784 N theta and N pi-(8alpha-Flavin) (on Histidine) 893 (Hex)3-HexNAc-HexNAc 1039 (Hex)3-HexNAc-(dHex)HexNAc