The carbonyl content in oxidized
BSA was determined using a protein carbonyl content detection kit
(Solarbio, Beijing China) as described by Levine et al.38 (link) A sample of 112 μΜ BSA was incubated
initially with 25 mM AAPH for 5 h and then derivated with 2,4-dinitrophenylhydrazine
(DNPH) for 60 min. The absorbance at 370 nm for the final dinitrophenylhydrazone
derivate was measured, and the carbonyl content was calculated according
to the method established by Baron et al.39 (link) and the recommendations by the manufacturer. Carbonyl groups in
both Lut and Cu(II)–Lut showed no activity in the reaction
with DNPH (data not shown), so their interference
with the study system can be ruled out. The contents of the carbonyl
group for the oxidation of BSA in the presence of Lut, Cu(II), and
the Cu(II)–Lut complex were corrected by subtracting the absorbance
of Lut, Cu(II), and the Cu(II)–Lut complex, respectively.
BSA was determined using a protein carbonyl content detection kit
(Solarbio, Beijing China) as described by Levine et al.38 (link) A sample of 112 μΜ BSA was incubated
initially with 25 mM AAPH for 5 h and then derivated with 2,4-dinitrophenylhydrazine
(DNPH) for 60 min. The absorbance at 370 nm for the final dinitrophenylhydrazone
derivate was measured, and the carbonyl content was calculated according
to the method established by Baron et al.39 (link) and the recommendations by the manufacturer. Carbonyl groups in
both Lut and Cu(II)–Lut showed no activity in the reaction
with DNPH (data not shown), so their interference
with the study system can be ruled out. The contents of the carbonyl
group for the oxidation of BSA in the presence of Lut, Cu(II), and
the Cu(II)–Lut complex were corrected by subtracting the absorbance
of Lut, Cu(II), and the Cu(II)–Lut complex, respectively.