| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2006: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2005: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Research Abstract |
Proteins, which consist of amino acids similarly with peptides, can appear their functions by folding to generate their own three-dimensional structures. However, it is generally difficult for short peptides to appear their functions, because they cannot fold up to their definite structures. In this study, we have designed and synthesized the artificial proteins, which consist of peptides containing an unnatural and coordinating amino acid, S'-amino-2,2'-bipyridine-S-carboxylic acid (5Bpy). The peptides containing a couple of residues of the unnatural amino acid are expected to coordinate with a metal ion, affording the artificial proteins with unique structural motifs. In particular, we would obtain the artificial proteins possessing the ruthenium tris(bipyridyl) type complex as the core, which should show unique photochemical/photophysical properties such as photo-induced electron or energy transfer and luminescent property.
Specifically, we have synthesized the 21-mer peptides with 3 residues of 5Bpy and two Pro-Gly sequences between 5Bpys. We have further synthesized the ruthenium complexes to yield four kinds of diastereomers. Each one has been successfully separated with HPLC techniques, and then identified with MALDI-TOF-MS. The chiral structures (Δ/Λ) around the ruthenium center have been determined from the CD spectral results. The structures of diastereomers have been determined by using 2D NMR (NOESY) and molecular modeling. The artificial proteins with a ruthenium complex have exhibit absorption around 470 nm and phosphorescence with a peak around 630 nm. This emissive property has allowed us to observe the artificial proteins in cells by using flow cytometry and a confocal laser scanning microscope
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