Lebedev V S, Volodina L A, Fedorov Iu I
Biofizika. 1991 Jan-Feb;36(1):91-6.
Characteristics of copper binding sites in the bacteria E. coli were studied using ESR spectroscopy. It was found that these cations had high local density on the strong binding range represented by the two type sites. The former include nitrogen and oxygen ligands and the second ones--sulfur of the thiol biomolecules. The weak coupling Cu(II) sites of E. coli represent more polar nitrogen-oxygen environment. Blocking SH-groups by N-ethylmaleimide makes them inaccessible for copper ligation, sharply increases the percentage of ESR-detectable copper of the strong-binding sites and prevents the membrane breakdown by these cations. The results suggest that the Cu(2+)-induced membrane damage is the effect of Cu2+ binding with the SH-containing sites of the bacterial membrane.
利用电子自旋共振光谱研究了大肠杆菌中铜结合位点的特征。研究发现，这些阳离子在由两种类型位点所代表的强结合范围内具有较高的局部密度。前者包括氮和氧配体，后者是硫醇生物分子中的硫。大肠杆菌的弱耦合Cu（II）位点代表了更多极性的氮-氧环境。用N-乙基马来酰亚胺阻断SH基团会使其无法与铜结合，大幅提高强结合位点中可被电子自旋共振检测到的铜的百分比，并防止这些阳离子导致的膜破裂。结果表明，Cu（2+）诱导的膜损伤是Cu2+与细菌膜含SH位点结合的结果。
