Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50383, Wroclaw, Poland.
Dalton Trans. 2011 Oct 28;40(40):10434-9. doi: 10.1039/c1dt10562k. Epub 2011 Jul 8.
The coordination properties of three peptides with CXXC motif: Ac-GCASCDNCRACKK-NH(2), Ac-GCASCDNCRAAKK-NH(2) and Ac-GCASCDNARAAKK-NH(2) as donors of four, three and two thiol ligands for Ni(2+),Cd(2+), Zn(2+) and Bi(3+) were studied by potentiometric titrations, UV-Vis and CD spectra measurements. Since the stability of the complexes is closely connected with the amount of the metal-bound cysteine sulfurs, competition plots of the complexes of peptides with 2, 3 and 4 cysteines further prove the involvement of all thiols in the metal ion binding. Furthermore, the sulfur-bound zinc complexes appear to be much more stable than the sulfur-bound nickel ones. The stabilities of the studied complexes decreases in the series Bi(3+) ≫ Cd(2+) > Zn(2+) > Ni(2+).
通过电位滴定、紫外-可见和 CD 光谱测量研究了具有 CXXC 基序的三个肽：Ac-GCASCDNCRACKK-NH(2)、Ac-GCASCDNCRAAKK-NH(2)和 Ac-GCASCDNARAAKK-NH(2)作为四个、三个和两个硫醇配体的供体，用于 Ni(2+)、Cd(2+)、Zn(2+)和 Bi(3+)。由于配合物的稳定性与金属结合半胱氨酸硫的数量密切相关，具有 2、3 和 4 个半胱氨酸的肽的配合物的竞争图进一步证明了所有硫醇都参与了金属离子结合。此外，硫结合的锌配合物似乎比硫结合的镍配合物稳定得多。研究的配合物的稳定性按 Bi(3+)≫Cd(2+)>Zn(2+)>Ni(2+)的顺序降低。
