Self-immobilizing Proteins

在自然界中，高度交联的蛋白质网络和其他生物聚合物是常见的材料。在许多情况下，酪氨酸侧链在受限区域内被酶氧化成活性中间体后，二酪氨酸交联会自发形成。该研究的总体目标是开发一种类似于天然二酪氨酸交联机制的新型位点特异性蛋白质固定化学。在合成的金属配体和遗传上附加在蛋白质上的金属结合肽之间的金属配合物，在温和氧化剂的存在下，策略性放置的酚基团（例如酪氨酸）之间的交联将被催化。具体来说，这一目标将通过：i.)肽金属结合配体组合文库的固态合成，ii.)快速的头上文库筛选

In nature, highly crosslinked networks of proteins and other biopolymers are common materials. In many cases, dityrosine crosslinks form spontaneously after tyrosine sidechains are enzymatically oxidized into reactive intermediates within a restricted region. The overall objective of the proposed research is to develop a novel site-specific protein immobilization chemistry similar to natural dityrosine crosslinking mechanisms. Crosslinks between strategicallly placed phenolic groups (e.g., tyrosine) will be catalyzed in the presence of a mild oxidant by a metal complex between a synthetic metal ligand and a metal binding peptide genetically appended to the protein. Specifically, this objective will be pursued by: i.) solid-state synthesis of combinatorial libraries of peptidic metal binding ligands, ii.) rapid on-bead library screening with labelled tyrosine-containing model peptides to discover a ternary metal complex that catalyzes dityrosine formation, iii.) optimization of catalytically active leads through refined searching within the positive parameter space, and iv.) testing of active complexes with model proteins to demonstrate the utility of self-immobilizing proteins. The proposed chemistry may have major advantages over existing protein modification methodologies. First, the proposed method does not rely on diffusible reagents that react with all accessible members of a particular class of nucleophilic functional group. Rather, protein modification will be localized to specific sites determined by the pre-formation of a ternary metal complex. Second, the protein modification site is determined genetically, eliminating the need for post-translational modification and allowing specific protein immobilization from complex mixtures. An important health related application of the proposed technology will be more efficient immobilization of proteins into arrays on solid supports. The widely expected future impact of protein arrays on clinical diagnosis and other areas of human health care may be realized more quickly with new and effective protein modification technology.