Reaction SMILES: [NH2:1][C@H:2]([C:5]([OH:7])=[O:6])[CH2:3][OH:4].N[C:9]([C:11](O)=[O:12])=C.[NH2:14][C@H:15]([C:22]([OH:24])=[O:23])[CH2:16][C:17]1N=C[NH:19][CH:18]=1>O>[NH:1]1[C:11](=[O:12])[CH2:9][CH2:3][C@H:2]1[C:5]([OH:7])=[O:6].[NH2:14][C@H:15]([C:22]([OH:24])=[O:23])[CH2:16][CH2:17][C:18](=[O:4])[NH2:19]
Reactant: N[C@@H](Cc1c[nH]cn1)C(=O)O
Reactant: N[C@@H](CO)C(=O)O
Reactant: C=C(N)C(=O)O
Solvent: O
Product: NC(=O)CC[C@H](N)C(=O)O
Product: O=C1CC[C@@H](C(=O)O)N1

Procedure:
A nonexclusive listing of possible protein modifications is as follows: 5′ dephospho; Desmosine (from Lysine); decomposed carboxymethylated Methionine; Ornithine (from Arginine); Lysinoalanine (from Cysteine); Lanthionine (from Cysteine); Dehydroalanine (from Cysteine); Homoserine formed from Met by CNBr treatment; Dehydration (—H2O); S-gamma-Glutamyl (crosslinked to Cysteine); O-gamma-Glutamyl-(Crosslink to Serine); Serine to Dehydroalanine; Alaminohistidine (Serine crosslinked to theta or pi carbon of Histidine); Pyroglutamic Acid formed from Gln; N-pyrrolidone carboxyl (N terminus); N alpha-(gamma-Glutamyl)-lysine; N-(beta-Aspartyl)-Lysine (Crosslink); 3,3′,5,5′-TerTyr (Crosslink); Disulphide bond formation (Cystine); S-(2-Histidyl)-(Crosslinked to Cysteine); S-(3-Tyr) (Crosslinked to Cysteine); 3,3′-BiTyr (Crosslink); IsodiTyr (Crosslink); Allysine (from Lysine); Amide formation (C terminus); Deamidation of Asparagine and Glutamine to Aspartate and Glutamate; Citruline (from Arginine); Syndesine (from Lysine); Methylation (N terminus, N epsilon of Lysine, O of Serine, Threonine or C terminus, N of Asparagine); delta-Hydroxy-allysine (from Lysine); Hydroxylation (of delta C of Lysine, beta C of Tryptophan, C3 or C4 of Proline, beta C of Aspartate); Oxidation of Methionine (to Sulphoxide); Sulfenic Acid (from Cysteine); Pyruvoyl-(Serine); 3,4-Dihydroxy-Phenylalanine (from Tyrosine) (DOPA); Sodium; Ethyl; N,N dimethylation (of Arginine or Lysine); 2,4-BisTrp-6,7-dione (from Tryptophan); Formylation (CHO); 6,7 Dione (from Tryptophan); 3,4,6-Trihydroxy-Phenylalanine (from Tyrosine) (TOPA); 3,4-Dihydroxylation (of Proline); Oxidation of Methionine (to Sulphone); 3-Chlorination (of Tyrosine with 35C1); 3-Chlorination (of Tyrosine with 37C1); Potassium; Carbamylation; Acetylation (N terminus, N epsilon of Lysine, O of Serine) (Ac); N-Trimethylation (of Lysine); gamma Carboxylation of Glutamate or beta Carboxylation of Aspartate; disodium; Nitro (NO2); t-butyl ester (OtBu) and t-butyl (tBu); Glycyl (-G-,-Gly-); Carboxymethyl (on Cystine); sodium+potassium; Selenocysteine (from Serine); 3,5-Dichlorination (of Tyrosine with 35C1); Dehydroalanine (Dha); 3,5-Dichlorination (of Tyrosine with mixture of 35C1 and 37C1)); Pyruvate; Acrylamidyl or Acrylamide adduct; Sarcosyl; Alanyl (-A-, -Ala-); Acetamidomethyl (Acm); 3,5-Dichlorination (of Tyrosine with 37C1); S-(sn-1-Glyceryl) (on Cysteine); Glycerol Ester (on Glutamic acid side chain); Glycine (G, Gly); Beta mercaptoethanol adduct; Phenyl ester (OPh) (on acidic); 3-Bromination (of Tyrosine with 79Br); Phosphorylation (O of Serine, Threonine, Tyrosine and Aspartate, N epsilon of Lysine); 3-Bromination (of Tyrosine with 81Br); Sulphonation (SO3H) (of PMC group); Sulphation (of O of Tyrosine); Cyclohexyl ester (OcHex); Homoseryl lactone; Dehydroamino butyric acid (Dhb); Gamma Aminobutyryl; 2-Aminobutyric acid (Abu); 2-Aminoisobutyric acid (Aib); Diaminopropionyl; t-butyloxymethyl (Bum); N-(4-NH2-2-OH-butyl)-(of Lysine) (Hypusine); Seryl (-S-, -Ser-); t-butylsulfenyl (StBu); Alanine (A, Ala); Sarcosine (Sar); Anisyl; Benzyl (Bzl) and benzly ester (OBzl); 1,2-ethanedithiol (EDT); Dehydroprolyl; Trifluoroacetyl (TFA); N-hydroxysuccinimide (ONSu, OSu); Prolyl (-P-, -Pro-); Valyl (-V-, -Val-); Isovalyl (-I-, -Iva-); t-Butyloxycarbonyl (tBoc); Threoyl (-T-, -Thr-); Homoseryl (-Hse-); Cystyl (-C-, -Cys-); Benzoyl (Bz); 4-Methylbenzyl (Meb); Serine (S, Ser); HMP (hydroxymethylphenyl) linker; Thioanisyl; Thiocresyl; Diphthamide (from Histidine); Pyroglutamyl; 2-Piperidinecarboxylic acid (Pip); Hydroxyprolyl (-Hyp-); Norleucyl (-Nle-); Isoleucyl (-I-, -Ile-); Leucyl (-L-, -Leu-); Ornithyl (-Orn-); Asparagyl (-N-, -Asn-); t-amyloxycarbonyl (Aoc); Proline (P, Pro); Aspartyl (-D-, -Asp-); Succinyl; Valine (V, Val); Hydroxybenzotriazole ester (HOBt); Dimethylbenzyl (diMeBzl); Threonine (T, Thr); Cysteinylation; Benzyloxymethyl (Bom); p-methoxybenzyl (Mob, Mbzl); 4-Nitrophenyl, p-Nitrophenyl (ONp); Cysteine (C, Cys); Chlorobenzyl (ClBzl); Iodination (of Histidine[C4] or Tyrosine[C3]); Glutamyl (-Q-, -Gln-); N-methyl Lysyl; Lysyl (-K-, -Lys-); O-Methyl Aspartamyl; Glutamyl (-E-, -Glu-); N alpha-(gamma-Glutamyl)-Glu; Norleucine (Nle); Hydroxy Aspartamyl; Hydroxyproline (Hyp); bb-dimethyl Cystenyl; Isoleucine (I, Ile); Leucine (L, Leu); Methionyl (-M-, -Met-); Asparagine (N, Asn); Pentoses (Ara, Rib, Xyl); Aspartic Acid (D, Asp); Dmob (Dimethoxybenzyl); Benzyloxycarbonyl (Z); Adamantyl (Ada); p-Nitrobenzyl ester (ONb); Histidyl (-H-, -His-); N-methyl Glutamyl; O-methyl Glutamyl; Hydroxy Lysyl (-Hyl-); Methyl Methionyl; Glutamine (Q, Gln); Aminoethyl Cystenyl; Pentosyl; Deoxyhexoses (Fuc, Rha); Lysine (K, Lys); Aminoethyl cystenyl (-AECys-); 4-Glycosyloxy-(pentosyl, C5) (of Proline); Methionyl Sulfoxide; Glutamic Acid (E, Glu); Phenylalanyl- (-F-, -Phe-); Pyridyl Alanyl; Fluorophenylalanyl; 2-Nitrobenzoyl (NBz); Methionine (M, Met); 3-methyl Histidyl; 2-Nitrophenylsulphenyl (Nps); 4-Toluenesulphonyl (Tosyl, Tos); 3-nitro-2-pyridinesulfenyl (Npys); Histidine (H, His); 3,5-Dibromination (of Tyrosine with 79Br); Arginyl (-R-, -Arg-); Citrulline; 3,5-Dibromination (of Tyrosine with mixture of 79Br and 81Br); Dichlorobenzyl (Dcb); 3,5-Dibromination (of Tyrosine with 81Br); Carboxyamidomethyl Cystenyl; Carboxymethyl Cystenyl; Methylphenylalanyl; Hexosamines (GalN, GlcN); Carboxymethyl cysteine (Cmc); N-Glucosyl (N terminus or N epsilon of Lysine) (Aminoketose); O-Glycosyl-(to Serine or Threonine); Hexoses (Fru, Gal, Glc, Man); Inositol; MethionylSulphone; Tyrosinyl (-Y-, -Tyr-); Phenylalanine (F, Phe); 2,4-dinitrophenyl (Dnp); Pentafluorophenyl (Pfp); Diphenylmethyl (Dpm); Phospho Seryl; 2-Chlorobenzyloxycarbonyl (ClZ); Napthyl acetyl; Isopropyl Lysyl; N-methyl Arginyl; Ethaneditohiol/TFA cyclic adduct; Carboxy Glutamyl (Gla); Acetamidomethyl Cystenyl; Acrylamidyl Cystenyl; Arginine (R, Arg); N-Glucuronyl (N terminus); delta-Glycosyloxy-(of Lysine or beta-Glycosyloxy-(of Phenylalanine or Tyrosine); 4-Glycosyloxy-(hexosyl, C6) (of Proline); Benzyl Seryl; N-methyl Tyrosinyl; p-Nitrobenzyloxycarbonyl (4Nz); 2,4,5-Trichlorophenyl; 2,4,6-trimethyloxybenzyl (Tmob); Xanthyl (Xan); Phospho Threonyl; Tyrosine (Y, Tyr); Chlorophenylalanyl; Mesitylene-2-sulfonyl (Mts); Carboxymethyl Lysyl; Tryptophanyl (-W-, -Trp-); N-Lipoyl-(on Lysine); Matrix alpha cyano MH+; Benzyl Threonyl; Benzyl Cystenyl; Napthyl Alanyl; Succinyl Aspartamyl; Succinimidophenyl carb.; HMP (hydroxymethylphenyl)/TFA adduct; N-acetylhexosamines (GalNAc, GlcNAc); Tryptophan (W, Trp); Cystine ((Cys)2); Farnesylation; S-Farnesyl-; Myristoleylation (myristoyl with one double bond); Pyridylethyl Cystenyl; Myristoylation; 4-Methoxy-2,3,6-trimethylbenzenesulfonyl (Mtr); 2-Bromobenzyloxycarbonyl (BrZ); Formyl Tryptophanyl; Benzyl Glutamyl; Anisole Adducted Glutamyl; S-cystenyl Cystenyl; 9-Flourenylmethyloxycarbonyl (Fmoc); Lipoic acid (amide bond to lysine); Biotinylation (amide bond to lysine); Dimethoxybenzhydryl (Mbh); N-Pyridoxyl (on Lysine); Pyridoxal phosphate (Schiff Base formed to lysine); Nicotinyl Lysyl; Dansyl (Dns); 2-(p-biphenyl)isopropyl-oxycarbonyl (Bpoc); Palmitoylation; “Triphenylmethyl (Trityl, Trt)”; Tyrosinyl Sulphate; Phospho Tyrosinyl; Pbf (pentamethyldihydrobenzofuransulfonyl); 3,5-Diiodination (of Tyrosine); 3,5-di-I″; N alpha-(gamma-Glutamyl)-Glu2; O-GlcNAc-1-phosphorylation (of Serine); “2,2,5,7,8-Pentamethylchroman-6-sulphonyl (Pmc)”; Stearoylation; Geranylgeranylation; S-Geranylgeranyl; 5′phos dCytidinyl; iodo Tyrosinyl; Aldohexosyl Lysyl; Sialyl; N-acetylneuraminic acid (Sialic acid, NeuAc, NANA, SA); 5′phos dThymidinyl; 5′phos Cytidinyl; Glutathionation; O-Uridinylylation (of Tyrosine); 5′phos Uridinyl; 5-farnesyl Cystenyl; N-glycolneuraminic acid (NeuGc); 5′phos dAdenosyl; O-pantetheinephosphorylation (of Serine); SucPhencarb Lysyl; 5′phos dGuanosyl; 5′phos Adenosinyl; O-5′-Adenosylation (of Tyrosine); 4′-Phosphopantetheine; GL2; S-palmityl Cystenyl; 5′phos Guanosyl; Biotinyl Lysyl; Hex-HexNAc; N alpha-(gamma-Glutamyl)-Glu3; Dioctyl Phthalate; PMC Lysyl; Aedans Cystenyl; Dioctyl Phthalate Sodium Adduct; di-iodo Tyrosinyl; PMC Arginyl; S-Coenzyme A; AMP Lysyl; 3,5,3′-Triiodothyronine (from Tyrosine); S-(sn-1-Dipalmitoyl-glyceryl)-(on Cysteine); S-(ADP-ribosyl)-(on Cysteine); N-(ADP-ribosyl)-(on Arginine); O-ADP-ribosylation (on Glutamate or C terminus); ADP-rybosylation (from NAD); S-Phycocyanobilin (on Cysteine); S-Heme (on Cysteine); N theta-(ADP-ribosyl)diphthamide (of Histidine); NeuAc-Hex-HexNAc; MGDG; O-8 alpha-Flavin [FAD])-(of Tyrosine); S-(6-Flavin [FAD])-(on Cysteine); N theta and N pi-(8alpha-Flavin) (on Histidine); (Hex)3-HexNAc-HexNAc; (Hex)3-HexNAc-(dHex)HexNAc.