9561345 Powell In this Small Business Innovation Research Phase I project, Undecagold, 1.4 nm "Nanogold" cluster complexes, combined fluorescent and gold cluster labels, and platinum cluster complexes 1.8 to 3.6 nm in diameter will be covalently conjugated to protected amino acids suitable for supported peptide synthesis. Analogs of L-cysteine, L-lysine and glycine will be prepared, in addition to labeling reagents functionalized to append the cluster labels to the N-terminal and C-terminal, and will be used to insert the labels at programmed positions in synthetic peptides during automated peptide synthesis. Chirality of the natural amino acids will be preserved to retain maximum peptide bioactivity. The labels will be synthetically modified for maximum solubility and stability towards synthesis and deprotection conditions by systematic variations of their coordinated ligands. Labeled peptide analogs of the C-terminal region of histone H1 protein, HMG-D and HMG-Z proteins will be prepared and microinjected into living cells. Their distribution, function and macromolecular localization within the cell nucleus will be studied by fluorescence confocal and electron microscopy. Labels will also be incorporated into synthetic analogs of the hormone peptide leuteinizing hormone releasing hormone (LHRH), then their sensitivity and specificity as immunoassay probes will be studied in membrane blot and microtiter plate tests. The reagents will be widely used by electron microscopists, cell and molecular biologists to prepare probes with the highest possible resolution, retention of bioactivity and sensitivity. The strategy for preparing labeled and unlabeled peptides simultaneously will reduce probe preparation time and cost. Rapidly growing applications exist in the selective labeling of combinatorial peptides. These reagents may also be used to prepare novel hybrid materials in which the unique electronic and catalytic properties of metal nanoparticles are programmed site-specif ically into new biomaterials to yield new macromolecular devices.
