Rózga Małgorzata, Sokołowska Magdalena, Protas Anna Maria, Bal Wojciech
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland.
J Biol Inorg Chem. 2007 Aug;12(6):913-8. doi: 10.1007/s00775-007-0244-8. Epub 2007 May 22.
The conditional stability constant at pH 7.4 for Cu(II) binding at the N-terminal site (NTS) of human serum albumin (HSA) was determined directly by competitive UV-vis spectroscopy titrations using nitrilotriacetic acid (NTA) as the competitor in 100 mM NaCl and 100 mM N-(2-hydroxyethyl)piperazine-N'-ethanesulfonic acid (Hepes). The log Kc (NTS) value of 12.0 +/- 0.1 was determined for HSA dissolved in 100 mM NaCl. A false log log Kc (NTS) (c) value of 11.4 +/- 0.1 was obtained in the 100 mM Hepes buffer, owing to the formation of a ternary Cu(NTA)(Hepes) complex. The impact of the picomolar affinity of HSA for Cu(II) on the availability of these ions in neurodegenerative disorders is briefly discussed.
在pH 7.4条件下，以次氮基三乙酸（NTA）作为竞争者，通过竞争性紫外-可见光谱滴定法，在100 mM氯化钠和100 mM N-（2-羟乙基）哌嗪-N'-乙磺酸（Hepes）中直接测定了人血清白蛋白（HSA）N端位点（NTS）上铜（II）结合的条件稳定常数。对于溶解在100 mM氯化钠中的HSA，测定的log Kc（NTS）值为12.0±0.1。在100 mM Hepes缓冲液中，由于形成了三元铜（NTA）（Hepes）络合物，得到了错误的log log Kc（NTS）（c）值11.4±0.1。简要讨论了HSA对铜（II）的皮摩尔亲和力对神经退行性疾病中这些离子可用性的影响。
