Jószai Viktória, Nagy Zoltán, Osz Katalin, Sanna Daniele, Di Natale Giuseppe, La Mendola Diego, Pappalardo Giuseppe, Rizzarelli Enrico, Sóvágó Imre
Department of Inorganic and Analytical Chemistry, University of Debrecen, P.O. Box 21, H-4010 Debrecen, Hungary.
J Inorg Biochem. 2006 Aug;100(8):1399-409. doi: 10.1016/j.jinorgbio.2006.04.003. Epub 2006 Apr 25.
Histidine-containing peptide fragments of prion protein are efficient ligands to bind various transition metal ions and they have high selectivity in metal binding. The metal ion affinity follows the order: Pd(II)>>Cu(II)>>Ni(II)Zn(II)>Cd(II) approximately Co(II)>Mn(II). The high selectivity of metal binding is connected to the involvement of both imidazole and amide nitrogen atoms in metal binding for Pd(II), Cu(II) and Ni(II), while only the monodentate N(im)-coordination is possible with the other metal ions. The stoichiometry and binding mode of palladium(II) complexes show great variety depending on the metal ion to ligand ratio, pH and especially the presence of coordinating donor atoms in the side chains of peptide fragments. It is also clear from our data that the peptide fragments containing histidine outside the octarepeat (His96, His111 and His187) are more efficient ligands than the monomer peptide fragments of the octarepeat domain.
朊病毒蛋白含组氨酸的肽片段是结合各种过渡金属离子的有效配体，并且它们在金属结合方面具有高选择性。金属离子亲和力顺序如下：Pd(II)>>Cu(II)>>Ni(II)>>Zn(II)>Cd(II)≈Co(II)>Mn(II)。金属结合的高选择性与咪唑和酰胺氮原子参与Pd(II)、Cu(II)和Ni(II)的金属结合有关，而其他金属离子仅可能形成单齿N(im)-配位。钯(II)配合物的化学计量和结合模式因金属离子与配体的比例、pH值，尤其是肽片段侧链中配位供体原子的存在而有很大差异。我们的数据还清楚表明，八肽重复序列之外含组氨酸的肽片段（His96、His111和His187）比八肽重复结构域的单体肽片段是更有效的配体。
