Protein sampleswere hydrolysed in 6 N HCl containing 1% phenol at
110 °C for 12 h in tubes sealed under nitrogen. The amino acidswere analyzed
by reversed-phase high performance liquid chromatography
(HPLC) after OPA/FMOC (o-phthalaldehyde/9-
fluorenylmethyloxycarbonyl) derivatisation [22].