Detail Photoinduced electron transfer in native proteins and domain forming polymers Bibliografi Author: Sheng, Yue ; Jones, Guilford II (Advisor) Topik: CHEMISTRY; BIOCHEMISTRY|CHEMISTRY; ANALYTICAL|CHEMISTRY; PHYSICAL Bahasa: (EN )    ISBN: 0-599-71817-X     Penerbit: Boston University     Tahun Terbit: 2001     Jenis: Theses - Dissertation Fulltext: 9967165.pdf (0.0B; 0 download) Abstract This study aims to elucidate photochemical electron transfer properties of semi-rigid molecules that show high affinity for native proteins and domain forming polymers. Proteins provide unique scaffolding or environments that are very different from homogenous solution. Two series of high affinity “photoligands” have been synthesized based on acridine and acridinium moieties to investigate the microenvironmental effects of protein binding. Acridinium-based electron donor-acceptor agents display a signature fluorescence that is associated with a charge-shift state which is remarkably sensitive to changes in medium. Electron transfer agents based on acridinium are designed de novo as protein-binding ligands. For an alternate system of pepsin and peptide-linked acridine complexes, spectroscopic studies show that the rate of intramolecular photoinduced electron transfer is significantly reduced upon binding to the protein. This electron transfer rate depends on the distance between the donor and acceptor; a through-bond electron transfer mechanism that depends on the population of peptide conformations is proposed. HPLC and other experiments show that there is strong binding between pepsin and photoligands. Competitive binding experiments confirm that these photoligands bind at the pepsin active site. This study demonstrates that fluorescence probes with high affinities for target native proteins may be designed and electron transfer properties can be characterized. The photochemical properties of the site-specific binding to a protein, bovine serum albumin (BSA), of acridinium derivatives based on 10-methylacridinium and 10-hexadecylacridinium have been examined. Dialysis of BSA/dye complexes show there is a strong binding between 10-hexadecylacridinium and BSA, while the 10-methylacridinium didn't show this property. Fluorescence quantum yield and lifetime studies reveal a binding between 10-hexadecylacridinium and BSA. Binding constant between 10-hexadecylacridinium and BSA is comparable to values observed for fatty acid - BSA complexation. A 13C NMR study showed that 10-hexadecylacridinium and fatty acid are competing for fatty acid binding sites with size-specific binding. The purpose of this study is to characterize fluorescence probes for BSA and related transport proteins that show high affinity and binding site differentiation. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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