In this work, N-n-amyl-N’-(sodium p- aminobenzenesulfonate) thiourea (APT) containing saturated fatty hydrocarbon group was synthesized. Fluorescence quenching methods in combination with UV absorption spectra and molecule modeling method were used to study the interaction between APT and bovine serum albumin (BSA) or human se-rum albumin (HSA). The binding constants of APT with BSA or HSA were determined at different tem-peratures under the optimum conditions based on the fluorescence quenching results. The binding characteristics of APT and BSA or HSA were reported and the binding sites were obtained. The binding mode was suggested to be mainly hydrophobic interaction, which was consistent with molecular modeling study.
CUI FenglingCUI YanruiLUO HongxiaYAO XiaojunFAN JingLU Yan
Calf thymus DNA was electrochemically oxidized at a multi-walled carbon nanotube modified electrode. The potentials for DNA oxidation at pH 7.0 were 0.71 and 0.81 V versus SCE, corresponding to the oxidation of guanine and adenine residues,respectively. The initial 6e-oxidation of adenine, observed in the first scan, resulted a quasi-reversible 2e-redox process of the oxidation product in the following scans.
In pH 5.5 phosphate buffer solution, N-n-undecyl-N＇-（sodium-p-amino-benzenesulfonate） thiourea （UPT） produced a pair of redox peaks on the bare glassy carbon electrode. At the multi-walled carbon nanotube （MWNT） modified electrode, the electrochemical behavior of UPT enhanced greatly. In the presence of bovine serum albumin （BSA）, the peak currents of UPT decreased linearly due to the formation of a super-molecular complex. This method was successfully applied to the determination of BSA in a bovine serum sample.
