Table 1.

Effect of amino acid modifying reagents on the binding activity

Reagent and concentration		Target	Inhibition of binding, %
DIDS	100 μM	Lys	37
	1 mM		80
Pyridoxal	2 mM	Lys	37
phosphate	20 mM		64
Phenyl glyoxal	1 mM	Arg	5
	10 mM		8
N-ethyl maleimide	2 mM	Cys	5
	20 mM		0
Phenylmethyl-	100 μM	Ser	0
sulphonyl fluoride	1 mM		0
Diethyl	1 mM	His	0
pyrocarbonate	10 mM		3

DIDS, 4-4′-diisothiocyanatostilbenne-2,2′-disulfonic acid. The different reagents were incubated during the binding assay (2 h, 0°C).