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Albumin‐bound low molecular weight thiols analysis in plasma and carotid plaques by CE

2009; Wiley; Volume: 33; Issue: 1 Linguagem: Inglês

10.1002/jssc.200900582

1615-9314

Angelo Zinellu, Antonio Junior Lepedda, Salvatore Sotgia, Elisabetta Zinellu, Giommaria Marongiu, Maria Franca Usai, Leonardo Gaspa, Pierina De Muro, Marilena Formato, Luca Deiana, Ciriaco Carru,

Lanthanide and Transition Metal Complexes

We describe a new method for the quantification of low molecular weight thiols, as homocysteine, cysteine, cysteinylglycine, glutamylcysteine and glutathione bound to human plasma albumin. After albumin isolation and purification by SDS-PAGE, thiols were freed from protein with tri-n-butylphosphine and successively derivatized with 5-iodoacetamidofluorescein. Samples were then injected and quantified in about 18 min by CE with laser induced fluorescence detection. Precision tests indicate a good repeatability of the method both for migration times (RSD<0.63%) and areas (RSD<2.98%). The method allows to measure all five low molecular weight thiols released from just 3 microg of albumin thus improving the other described methods in which only three or four thiols were detected. Due to the elevated sensitivity (LOD of 0.3 pM for all thiols), also low molecular weight thiols bound to albumin filtered in tissues could be quantified.