From: Combinatorial peptidomics: a generic approach for protein expression profiling
Reagents | Group specificity | Crossreactivity |
---|---|---|
α Haloacetyl compounds: Iodoacetate; α haloacetamides; bromotrifluoroacetone; N chloroacetyliodotyramine | Cys, His, Met, Tyr | NH2 groups (slow at low pH) |
N Maleimide derivatives: N ethylmaleimide (at pH < = 7) | Cys | NH2 groups (slow at low pH) |
Mercurial compounds (most specific): p chloromercuribenzoate(PCMB)/p hydroxymercuribenzoate(PHMB) in H2O (optimum at pH 5, competitive displacement possible) | Cys | Â |
Disulphide reagents (reversible): 5,5 dithiobis (2 nitrobenzoic acid) (DTNB); 4,4 dithiodipyridine; methyl 3 nitro 2 pyridyl disulphide; methyl 2 pyridyl disulphide | Cys | Â |
N acetylimidazole | Tyr | NH2 groups (slow) |
Diazonium compounds (optimum at pH9, unstable) | Tyr, His | NH2, Trp, Cys and Arg (slow) |
Dicarbonyl compounds (pH > = 7): glyoxal; phenylglyoxal; 2,3 butanedione; 1,2 cyclohexanedione | Arg | Lys at pH < = 7 |
p toluenesulphonylphenyl alaninechloromethyl ketone (TPCK); p toluenesulphonyllysine chloromethyl ketone (TLCK); Methyl-p-nitrobenzenesulphonate | His | Cys |
Diethylpyrocarbonate (reversible at pH > = 7) | His (at pH4) | NH2 |
2 hydroxy 5 nitrobenzyl bromide (HNBB) | Trp | Â |
p nitrophenylsulphenyl chloride | Trp, Cys | Â |
α Haloacetyl compounds | Met at pH3; also Cys, His, Tyr | NH2 groups (slow at low pH) |