Delta Mass

A database of protein post
Translational modifications

The ABRF accepts no responsibility for the accuracy of these data which are freely donated by individuals.

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Average Masses

Avg. Mass Change Modification
-795' dephospho
-58Desmosine (from Lysine)
-48decomposed carboxymethylated Methionine
-44Decarboxylation of gamma carboxy Glutamate
-43Gamma-glutamyl semialdehyde (from arginine)
-42Ornithine (from Arginine)
-34Lysinoalanine (from Cysteine)
-34Lanthionine (from Cysteine)
-34Dehydroalanine (from Cysteine)
-30Homoserine formed from Met by CNBr treatment
-27Oxidation of arginine (to glutamic acid)
-18Formylglycine (from cysteine)
-18Pyroglutamic Acid formed from Glutamic Acid
-18Dehydration (-H2O)
-18S-gamma-Glutamyl (crosslinked to Cysteine)
-18O-gamma-Glutamyl- (Crosslink to Serine)
-18Serine to Dehydroalanine
-18Alaninohistidine (Serine crosslinked to theta or pi carbon of Histidine)
-18Misincorporation of Norleucine for Methionine
-18Succinimide formation from aspartic acid
-17Pyroglutamic Acid formed from Gln
-17N-pyrrolidone carboxyl (N terminus)
-17N alpha -(gamma-Glutamyl)-lysine
-17N-(beta-Aspartyl)-Lysine (Crosslink)
-17Succinimide formation from asparagine
-17S-carbamoylmethylcysteine cyclization (N-terminus)
-16Pyruvoyl- (Serine)
-5Crosslink between Arg and His sidechains
-43,3',5,5'-TerTyr (Crosslink)
-2Formylglycine (from serine)
-2Disulphide bond formation (Cystine)
-2S-(2-Histidyl)- (Crosslinked to Cysteine)
-2S-(3-Tyr) (Crosslinked to Cysteine)
-23,3'-BiTyr (Crosslink)
-2IsodiTyr (Crosslink)
-1Allysine (from Lysine)
-1Amide formation (C terminus)
-1Oxidation of lysine (to aminoadipic semialdehyde)
1Deamidation of Asparagine and Glutamine to Aspartate and Glutamate
1Citruline (from Arginine)
2ysteine x2, reduction of Cystine (Cys-Cys)
2Reduction of indole double bond of Trp
4Oxidation of Trp to kynurenine
12Lysine epsilon amino to imine
12Cysteine (N-term) formaldehyde adduct (Cys to Thioproline conversion)
12Formaldehyde adduct of Trp
13Syndesine (from Lysine)
13CM-Cys vs PAM-Cys
14Methylation (N terminus, N epsilon of Lysine, O of Serine, Threonine or C terminus, N of Asparagine)
14CAM-Cys vs PAM-Cys
14Methylation (methyl esterification of Asp and Glu side chains)
15Delta-Hydroxy-allysine (from Lysine)
15Oxidation of lysine (to aminoadipic acid)
16Hydroxylation (of delta C of Lysine, beta C of Tryptophan, C3 or C4 of Proline, beta C of Aspartate)
16Oxidation of Methionine (to Sulphoxide)
163,4-Dihydroxy-Phenylalanine (from Tyrosine) (DOPA)
16Oxohistidine (from histidine)
16Sulfenic Acid (from Cysteine)
16Oxidation of proline (to gamma-glutamyl semialdehyde)
22Sodium
28Ethyl
28N,N dimethylation (of Arginine or Lysine)
282,4-BisTrp-6,7-dione (from Tryptophan)
28Formylation (CHO)
306,7 Dione (from Tryptophan)
323,4,6-Trihydroxy-Phenylalanine (from Tyrosine) (TOPA)
323,4-Dihydroxylation (of Proline)
32Oxidation of Methionine (to Sulphone)
32Oxidation of proline (to glutamic acid)
32Double oxidation of Trp
32Trisulfide bond (additional sulfur in disulfide bond)
343-Chlorination (of Tyrosine with 35Cl)
363-Chlorination (of Tyrosine with 37Cl)
38Potassium
42Acetylation (N terminus, N epsilon of Lysine, O of Serine) (Ac)
42N-Trimethylation (of Lysine)
43Carbamylation
44disodium
45Nitro (NO2)
46beta-Methylthio-aspartic acid
48Cysteic acid, oxidation of cysteine
51Piperidine adduct to C-terminal Cys
56t-butyl ester(OtBu) and t-butyl (tBu)
57Glycyl (-G-,-Gly-)
57Carboxamidomethyl (on Cysteine and other residues)
58Carboxymethyl (on Cysteine and other residues)
60sodium + potassium
64Selenocysteine (from Serine)
67Asp transamidation with piperidine
683,5-Dichlorination (of Tyrosine with 35Cl)
69Dehydroalanine (Dha)
703,5-Dichlorination (of Tyrosine with mixture of 35Cl and 37Cl))
70Pyruvate
71Sarcosyl
71Alanyl (-A-, -Ala-)
71Acetamidomethyl (Acm)
71Propionamide or Acrylamide adduct
723,5-Dichlorination (of Tyrosine with 37Cl)
74S-(sn-1-Glyceryl) (on Cysteine)
74Glycerol Ester (on Glutamic acid side chain)
75Glycine (G, Gly)
76Phenyl ester (OPh) (on acidic)
76Beta mercaptoethanol adduct
783-Bromination (of Tyrosine with 79Br)
783-o-bromination of Phe with 79Br
80L-o-bromination of Phe with 81Br
80Sulphonation (SO3H) (of PMC group)
80Sulphation (of O of Tyrosine)
80Phosphorylation (O of Serine, Threonine, Tyrosine and Aspartate, N epsilon of Lysine)
803-Bromination (of Tyrosine with 81Br)
82Cyclohexyl ester (OcHex)
83Homoseryl lactone
83Homoseryl lactone
852-Aminobutyric acid (Abu)
852-Aminoisobutyric acid (Aib)
85Gamma Aminobutyryl
86t-butyloxymethyl (Bum)
86Diaminopropionyl
87N-(4-NH2-2-OH-butyl)- (of Lysine) (Hypusine)
87Seryl (-S-, -Ser-)
88t-butylsulfenyl (StBu)
89Alanine (A, Ala)
89Sarcosine (Sar)
90Anisyl
90Benzyl (Bzl) and benzly ester (OBzl)
931,2-ethanedithiol (EDT)
95Dehydroprolyl
96Trifluoroacetyl (TFA)
97N-hydroxysuccinimide (ONSu, OSu)
97Prolyl (-P-, -Pro-)
98Cysteic acid x2, oxidation of cystine
98Tetramethylguanidinium termination by-product on amine
98Phosphate/sulphate adduct of proteins
99Valyl (-V-, -Val-)
99Isovalyl (-I-,-Iva-)
100t-Butyloxycarbonyl (tBoc)
101Threoyl (-T-, -Thr-)
101Homoseryl (-Hse-)
103Cystyl (-C-, -Cys-)
1044-Methylbenzyl (Meb)
104Benzoyl (Bz)
105Serine (S, Ser)
105Pyridylethylation of cysteine
106HMP (hydroxymethylphenyl) linker
106Thioanisyl
106Thiocresyl
1112-Piperidinecarboxylic acid (Pip)
111Pyroglutamyl
113Hydroxyprolyl (-Hyp-)
113Isoleucyl (-I-, -Ile-)
113Leucyl (-L-, -Leu-)
113Norleucyl (-Nle-)
114Asparagyl (-N-, -Asn-)
114t-amyloxycarbonyl (Aoc)
114Ornithyl (-Orn-)
115Proline (P, Pro)
115Aspartyl (-D-, -Asp-)
117Succinyl
117Valine (V, Val)
117Hydroxybenzotriazole ester (HOBt)
118Dimethylbenzyl (diMeBzl)
119Threonine (T, Thr)
119Cysteinylation
120Benzyloxymethyl (Bom)
120p-methoxybenzyl (Mob, Mbzl)
1214-Nitrophenyl, p-Nitrophenyl (ONp)
121Cysteine (C, Cys)
125Chlorobenzyl (ClBzl)
126Iodination (of Histidine[C4] or Tyrosine[C3])
126octanoylation
128Glutamyl (-Q-, -Gln-)
128Lysyl (-K-, -Lys-)
129Glutamyl (-E-, -Glu-)
129O-Methyl Aspartamyl
130N alpha -(gamma-Glutamyl)-Glu
131Norleucine (Nle)
131Hydroxyproline (Hyp)
131Isoleucine (I, Ile)
131Leucine (L, Leu)
131Methionyl (-M-, -Met-)
131Hydroxy Aspartamyl
131bb-dimethyl Cystenyl
132Asparagine (N, Asn)
132Pentoses (Ara, Rib, Xyl)
133Aspartic Acid (D, Asp)
134Benzyloxycarbonyl (Z)
134Adamantyl (Ada)
135p-Nitrobenzyl ester (ONb)
137Histidyl (-H-, -His-)
142N-methyl Glutaminyl
142N-methyl Lysyl
143O-methyl Glutamyl
143Diphthamide (from Histidine)
144Hydroxy Lysyl (-Hyl-)
145Methyl Methionyl
146Glutamine (Q, Gln)
146Deoxyhexoses (Fuc, Rha)
146Lysine (K, Lys)
146Pentosyl
146Aminoethyl Cysteinyl (AECys)
1474-Glycosyloxy- (pentosyl,C5) (of Proline)
147Glutamic Acid (E, Glu)
147Phenylalanyl- (-F-, -Phe-)
147Methionyl Sulfoxide
148Pyridyl Alanyl
1492-Nitrobenzoyl (NBz)
149Methionine (M, Met)
149Fluorophenylalanyl
150Dimethoxybenzyl Trp
1532-Nitrophenylsulphenyl (Nps)
1544-Toluenesulphonyl (Tosyl, Tos)
1543-nitro-2-pyridinesulfenyl (Npys)
155Histidine (H, His)
1563,5-Dibromination (of Tyrosine with 79Br)
156Arginyl (-R-, -Arg-)
157Citrulline
1583,5-Dibromination (of Tyrosine with mixture of 79Br and 81Br)
159Dichlorobenzyl (Dcb)
1603,5-Dibromination (of Tyrosine with 81Br)
160Carboxyamidomethyl Cystenyl
161Hexosamines (GalN, GlcN)
161Carboxymethyl cysteine (Cmc)
161Carboxymethyl Cystenyl
161Methylphenylalanyl
162Inositol
162N-Glucosyl (N terminus or N epsilon of Lysine) (Aminoketose)
162O-Glycosyl- (to Serine or Threonine)
162Linker attached to peptide in Fmoc peptide synthesis
162Hexoses (Fru, Gal, Glc, Man)
163Tyrosinyl (-Y-, -Tyr-)
163MethionylSulphone
165Phenylalanine (F, Phe)
1662,4 -dinitrophenyl (Dnp)
166Pentaflourophenyl (Pfp)
166Diphenylmethyl (Dpm)
167Phospho Seryl
1692-Chlorobenzyloxycarbonyl (ClZ)
169Napthyl acetyl
170N-acetyl Lysyl
170N-methyl Arginyl
170Decanoic acid modification of Cys in active site
172Ethanedithiol/TFA cyclic adduct
173Carboxy Glutamyl (Gla)
174Arginine (R, Arg)
174Acetamidomethyl Cystenyl
174Acrylamidyl Cystenyl
176N-Glucuronyl (N terminus)
177delta-Glycosyloxy- (of Lysine) or beta-Glycosyloxy- (of Phenylalanine or Tyrosine)
1774-Glycosyloxy- (hexosyl,C6) (of Proline)
177Benzyl Seryl
177N-methyl Tyrosinyl
178a-N-Gluconoylation (His Tagged proteins)
179p-Nitrobenzyloxycarbonyl (4Nz)
1792,4,5-Trichlorophenyl
1802,4,6-trimethyloxybenzyl (Tmob)
180Xanthyl (Xan)
181Tyrosine (Y, Tyr)
182Chlorophenylalanyl
182Mesitylene-2-sulfonyl (Mts)
183AEBSF
184Isopropyl Lysyl
186Tryptophanyl (-W-, - Trp-)
186Carboxymethyl Lysyl
188N-Lipoyl- (on Lysine)
190Matrix alpha cyano MH+
191Benzyl Threonyl
193Benzyl Cystenyl
197Napthyl Alanyl
198Succinyl Aspartamyl
201HMP (hydroxymethylphenyl)/TFA adduct
203N-acetylhexosamines (GalNAc, GlcNAc)
204Tryptophan (W, Trp)
204Cystine ((Cys)2)
204Farnesylation
206S-Farnesyl-
206Myristoylation-4H (2 double bonds)
208Myristoleylation (myristoyl with one double bond)
208Pyridylethyl Cystenyl
210Myristoylation
2124-Methoxy-2,3,6-trimethylbenzenesulfonyl (Mtr)
2132-Bromobenzyloxycarbonyl (BrZ)
214Formyl Tryptophanyl
219Benzyl Glutamyl
219Anisole Adducted Glutamyl
2229-Fluorenylmethyloxycarbonyl (Fmoc)
222S-cystenyl Cystenyl
226Biotinylation (amide bond to lysine)
226Dimethoxybenzhydryl (Mbh)
229N-Pyridoxyl (on Lysine)
231Pyridoxal phosphate (Schiff Base formed to lysine)
233Dansyl (Dns)
233Nicotinyl Lysyl
2382-(p-biphenyl)isopropyl-oxycarbonyl (Bpoc)
238Palmitoylation
242Triphenylmethyl (Trityl, Trt)
243Tyrosinyl Sulphate
243Phospho Tyrosinyl
252Pbf (pentamethyldihydrobenzofuransulfonyl)
2523,5-Diiodination (of Tyrosine)
258a-N-6-Phosphogluconoylation (His Tagged proteins)
259N alpha -(gamma-Glutamyl)-Glu2
266Stearoylation
266Pmc (2,2,5,7,8- Pentamethylchroman-6-sulphonyl)
272Geranylgeranylation
272Monomethoxytrityl
276S-Geranylgeranyl
283O-GlcNAc-1-phosphorylation (of Serine)
2895'phos dCytidinyl
289iodo Tyrosinyl
290Aldohexosyl Lysyl
291Sialyl
291N-acetylneuraminic acid (Sialic acid, NeuAc, NANA, SA)
3045'phos dThymidinyl
3055'phos Cytidinyl
305Glutathionation
306O-Uridinylylation (of Tyrosine)
3065'phos Uridinyl
307N-glycolneuraminic acid (NeuGc)
307S-farnesyl Cystenyl
3135'phos dAdenosyl
324O-pantetheinephosphorylation (of Serine)
327SucPhencarb Lysyl
3295'phos dGuanosyl
3295'phos Adenosinyl
329O-5'-Adenosylation ( of Tyrosine)
3394'-Phosphopantetheine
342S-palmityl Cystenyl
3455'phos Guanosyl
354Biotinyl Lysyl
359Fluorescein labelling of peptide N-terminal using NHS ester
365Hex-HexNAc
388N alpha -(gamma-Glutamyl)-Glu3
391Dioctyl Phthalate
395PMC Lysyl
409Aedans Cystenyl
413Dioctyl Phthalate Sodium Adduct
415di-iodo Tyrosinyl
423PMC Arginyl
454S-Coenzyme A
457AMP Lysyl
4703,5,3'-Triiodothyronine (from Tyrosine)
524S-(sn-1-Dipalmitoyl-glyceryl)- (on Cysteine)
541S-(ADP-ribosyl)- (on Cysteine)
541N-(ADP-ribosyl)- (on Arginine)
541O-ADP-ribosylation (on Glutamate or C terminus)
541ADP-rybosylation (from NAD)
617S-Heme (on Cysteine)
648N theta -(ADP-ribosyl) diphthamide (of Histidine)
657NeuAc-Hex-HexNAc
783O-8 alpha-Flavin [FAD])- (of Tyrosine)
784S-(6-Flavin [FAD])- (on Cysteine)
784N theta and N pi-(8alpha-Flavin) (on Histidine)
893(Hex)3-HexNAc-HexNAc
1,039(Hex)3-HexNAc-(dHex)HexNAc