Design of a Selective Metal Ion Switch for Self-Assembly of Peptide-Based Fibrils

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• 作者：Steven N. Dublin ; Vincent P. Conticello
• 刊名：Journal of the American Chemical Society
• 出版年：2008
• 出版时间：January 9, 2008
• 年：2008
• 卷：130
• 期：1
• 页码：49 - 51
• 全文大小：144K
• 年卷期：v.130,no.1(January 9, 2008)
• ISSN：1520-5126

文摘

The self-assembling peptide TZ1H, a structural variant of the trimeric isoleucine zipper GCN4-pII, contains histidine residues at core d-positions of alternate heptads that define three trigonal coordination sites within the coiled-coil trimer. Circular dichroism spectropolarimetry indicated that peptide TZ1H undergoes a random coil to -helical conformational change upon binding of 1 equiv of silver(I) ion, but not zinc(II), copper(II), or nickel(II) ions. Isothermal titration calorimetry provided evidence for a single binding-site model in which each peptide contributes one net silver(I) coordination site, in agreement with the proposed structural model. Transmission electron microscopy revealed that TZ1H self-assembles into long aspect ratio helical fibers in the presence of silver(I) ion. These results demonstrate that the rational design of selective metal ion binding sites within de novo designed peptides represents a promising approach to the controlled fabrication of nanoscale, self-assembled materials.