Maleimido-proxyl as an EPR spin label for the evaluation of conformational changes of albumin

摘要: Albumin is the most abundant plasma protein and as such has been subject of many studies using a variety techniques. One them, capable monitoring conformational changes binding capacity proteins, electron paramagnetic resonance spectroscopy (EPR) spin labeling. To date, albumin investigated number different labels, mostly spin-labeled fatty acids (SLFAs). However, can bind up to seven equivalents acids, making it difficult determine which parts molecule undergo changes. obtain information from specific site on protein, labels that free cysteine residues may be used. In this work, applicability label, 3-maleimido proxyl (5-MSL), was evaluated for bovine serum (BSA) at temperatures pH values. Also, effect ethanol, reactive oxygen species (hydrogen peroxide superoxide radical), ligands albumin, namely several drugs were evaluated. The results indicate labeling its residue (Cys-34) 5-MSL successfully used detection changes, even in case subtle alterations induced by ligand binding.