KCN-1 is known to reduce tumor growth 6-fold in mice implanted with LN229 glioma cells. Although this inhibitor is effective, the mechanism of action for KCN-1 is not well understood. Based on preliminary studies, KCN-1 reduces tumor growth by disrupting the HIF 1 (hypoxia-induced factor-1) pathway. The binding target of KCN-1 needs to be investigated in order to develop KCN-1 or its analogs for therapeutic applications. In this research, a molecule was designed and synthesized for the identification of the binding target of KCN-1. Specifically, this molecule contains the inhibitor (KCN-1), a photocleavable linker, beads, and the affinity label (L DOPA). When UV light shines on the linker, the trans-alkene isomerizes to cis-alkene and undergoes intramolecular ring-closing reaction, which helps cleave the immobilized bead from the linker. The immobilized bead is used to separate the binding fragment attached to the photocleavable linker from the solution after enzyme digestion. The affinity label (L-DOPA) reacts with a nucleophile from the binding target and creates a covalent bond. If the design is successful, this method is able to analyze the mass of the peptide sequence and determine the binding target of KCN-1.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19035号 / 農博第2113号 / 新制||農||1031(附属図書館) / 学位論文||H27||N4917(農学部図書室) / 31986 / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 宮川 恒, 教授 西田 律夫, 教授 間藤 徹 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Diese Arbeit beschäftigt sich mit der Synthese neuer photoreaktiver Polymere, die bei Bestrahlung mit Licht (Hg-Dampflampe, fs-gepulster Ti:Sa-Laser) definierte Reaktionen durchlaufen. Mittels kontrolliert-radikalischer Polymerisation und anschließender polymeranaloger Reaktion wurden verschiedene Azobenzen-Derivate, Arylazosulfonat-Derivate und photolabil geschützte Aminogruppen (Nitroveratryloxycarbonyl, Nvoc) in Methacrylat-Polymere eingeführt. Diese Strukturen wurden ausführlich hinsichtlich ihrer Struktur und vor allem ihrer photochemischen Eigenschaften (Extinktionskoeffizienten, Zerfallskinetik) untersucht. Dünne Schichten (d<30nm) der so hergestellten Materialien wurden bei der Entwicklung einer neuen photolithographischen Methode, der plasmonischen Nanolithographie, eingesetzt.

Antigen presentation and recognition are key processes of the immune system necessary to initiate the adaptive immune response. Longstanding goals of these fields have been to understand the molecular mechanism of MHC II-peptide binding, the way in which dysregulation of this process can lead to disease, and determining how γδTCRs recognize their ligands. To examine some of these outstanding questions, I designed photocleavable peptides that could bind HLA-DR1 and could be used to facilitate peptide exchange. I also performed studies to understand whether peptide exchange on HLA-DR1 can be affected by glycation modifications, which occur in hyperglycemic conditions such as diabetes. I observed that while glycation modifications on HLA-DR1 did not affect peptide exchange, these modifications decreased the catalytic effect of HLA-DM on this reaction, which could affect antigen presentation in diabetic patients. For studies on antigen recognition by γδTCRs, I focused on γδNKT cells, a subset of γδT cells known to play a role during Listeria infection. I used four different variants of the γδNKT TCR to study the restrictions on Vγ junctional region usage by this TCR for ligand recognition. I found that all the TCR variants I examined could recognize cells infected with Listeria, indicating that this TCR is not restricted by γ-chain usage in order to recognize ligand. My research generated reagents that could serve in future studies of HLA-DR1 peptide binding and contributed to understanding the effect of hyperglycemic conditions on antigen presentation, as well as provided greater understanding of γδTCR restriction for ligand recognition.

<p>The goal of this research project is to synthesize, characterize, and examine the properties of a material that undergoes a decrease in refractive index upon exposure to light. It is anticipated that such photoresponses could elicit previously unknown nonlinear phenomena including self-trapped black beams. An appropriate material for these investigations would be a polymer cross-linked by photocleavable groups causing a Δ<em>n</em> < 0. Organo-ditellurides, molecules that contain a Te-Te bond, would be appropriate for the crosslinks as their σ*_Te-Te ← n_Te transition usually absorbs light between 400 and 500 nm, and can lead to photodissociation of the chalcogen-chalcogen bond.</p> <p>Initial attempts to directly functionalize a polymer (polystyrene) resulted in intractable solids. A more promising approach relies on the preparation of cross-linking agents followed by co-polymerization. Despite literature claims, to date, there is no structurally authenticated photoresponsive molecule that simultaneously contains vinyl (CH=CH) and telluride (-Te-) functional groups. The work in this thesis has yielded what would be the first example, in addition to a crystal structure obtained by X-ray diffraction, the compound has been characterized by multinuclear NMR (¹H, ¹³C, ¹²⁵Te) and vibrational spectroscopy with the support of DFT calculations.</p> / Master of Science (MSc)

No description available.

Diese Arbeit beschäftigt sich mit der Synthese neuer photoreaktiver Polymere, die bei Bestrahlung mit Licht (Hg-Dampflampe, fs-gepulster Ti:Sa-Laser) definierte Reaktionen durchlaufen. Mittels kontrolliert-radikalischer Polymerisation und anschließender polymeranaloger Reaktion wurden verschiedene Azobenzen-Derivate, Arylazosulfonat-Derivate und photolabil geschützte Aminogruppen (Nitroveratryloxycarbonyl, Nvoc) in Methacrylat-Polymere eingeführt. Diese Strukturen wurden ausführlich hinsichtlich ihrer Struktur und vor allem ihrer photochemischen Eigenschaften (Extinktionskoeffizienten, Zerfallskinetik) untersucht. Dünne Schichten (d<30nm) der so hergestellten Materialien wurden bei der Entwicklung einer neuen photolithographischen Methode, der plasmonischen Nanolithographie, eingesetzt.:INHALTSVERZEICHNIS ABBILDUNGSVERZEICHNIS TABELLENVERZEICHNIS ABKÜRZUNGS- UND SYMBOLVERZEICHNIS 1 EINLEITUNG UND ZIELSTELLUNG 2 THEORETISCHE GRUNDLAGEN 2.1 PHOTOREAKTIVE POLYMERE 2.1.1 Azobenzenhaltige Polymere und deren Anwendungen 2.1.2 Arylazosulfonathaltige Polymere und deren Anwendungen 2.1.3 Photolabil geschützte Amine in Polymeren und zur Oberflächenstrukturierung 2.2 NICHT-LINEAR OPTISCHE EFFEKTE - FREQUENZVERDOPPLUNG 2.3 OBERFLÄCHENPLASMONENRESONANZ UND SHG AN METALLISCHEN NANOPARTIKELN 2.4 PHOTOCHEMISCHE STRUKTURIERUNG DÜNNER SCHICHTEN 2.5 NANOLITHOGRAPHISCHE STRUKTURIERUNG MITTELS PLASMONISCHER EFFEKTE AN METALLNANOSTRUKTUREN 3 ERGEBNISSE UND DISKUSSION 3.1 AZOBENZENHALTIGE POLYMERE 3.1.1 Synthese niedermolekularer Azobenzen-Derivate 3.1.2 Anbindung an Polymermatrix 3.1.3 Photochemische matrixabhängige Untersuchung der Isomerisationskinetik 3.1.4 Bestrahlung in dünnen Schichten mit gepulstem Femtosekunden-Laser 3.2 ARYLAZOSULFONATHALTIGE POLYMERE 3.2.1 Kontrolliert-radikalische Polymerisation von Arylazosulfonat-Monomeren 3.2.1.1 Synthese der arylazosulfonathaltigen Monomere 3.2.1.2 RAFT-Polymerisation von (AS-Mon2) 3.2.2 Polymeranaloge Einführung von Arylazosulfonateinheiten 3.2.3 Präparation und Bestrahlung dünner Schichten 3.3 PHOTOLABIL GESCHÜTZTE AMINOPOLYMERE 3.3.1 Synthese von statistischen Nvoc-geschützten Aminocopolymeren 3.3.1.1 Anbindung des Nvoc-geschützten Amins über Esterbindung 3.3.1.2 Anbindung des Nvoc-geschützten Amins über Reaktion mit Nvoc-Cl 3.3.2 Nvoc-haltige Diblockcopolymere 3.3.2.1 Synthese von P(MMA-co-GMA)-b-P(MMA-co-NvocCMS) 3.3.2.2 Synthese von P(MMA-co-MAA)-b-P(MMA-co-NvocAEMA) 3.3.3 Präparation dünner Schichten der (Block-)Copolymere 3.3.4 Bestrahlung mit gepulstem Femtosekunden-Laser 4 ZUSAMMENFASSUNG UND AUSBLICK 5 EXPERIMENTALTEIL 5.1 ANALYTISCHE METHODEN 5.2 AUFBAU FÜR DIE FS-LASER-BESTRAHLUNG 5.3 VERWENDETE CHEMIKALIEN 5.4 SYNTHESEN 5.4.1 Azobenzen-Derivate 5.4.1.1 Niedermolekulare Verbindungen 5.4.1.2 Polymerisationen und polymeranaloge Reaktionen 5.4.2 Arylazosulfonate 5.4.2.1 Niedermolekulare Verbindungen 5.4.2.2 Freie radikalische Polymerisation 5.4.2.3 RAFT-Polymerisationenen 5.4.2.4 Polymeranaloge Reaktion 5.4.3 Nvoc-geschützte (Block-)Copolymere 5.4.3.1 Niedermolekulare Verbindungen 5.4.3.2 Polymerisationen 5.4.3.3 Polymeranaloge Reaktionen 5.5 WAFERREINIGUNG UND PRÄPARATION DÜNNER SCHICHTEN LITERATURVERZEICHNIS DANKSAGUNG VERSICHERUNG

During recent decades metallic nanoparticles have been found very interesting due to their unique characteristics which make them suitable for different applications. In this research, for the very first time, we tried to perform selective surface photo activation chemistry on the targeted facets of nanoparticles while they are in suspension. This technique enabled us to form desired assemblies of nanoparticles. We focused on elongated shaped gold nanorod due to its unique surface plasmon resonance and probable biomedical applications. In this research we formed a dumbbell shape assembly of nanoparticles in suspension. A probable application for these assemblies can be in vivo imaging. Initially, we reproduced gold nanorods using existing techniques in prior papers and optimized them according to our research needs. A low rpm centrifugal separation technique was developed to efficiently separate synthesized gold nanorods from other shapes. Several characterization techniques were utilized to characterize nanoparticles at each step including UV-absorbance, zeta potential, and dynamic light scattering. Different generations of oligomers were synthesized to be used as gold nanorods coating, and each coating was tested and characterized using appropriate techniques. Our two-step coating replacement method using one of these photocleavable oligomers enabled us to achieve, for the very first time, selective UV photo activation of gold nanorod tips. The photo activated tips were then exposed to oppositely charged gold nanospheres to form dumbbell shape assemblies of gold nanorods and nanospheres. Furthermore, dumbbell shape assembly of nanoparticles was investigated and characterized. / Master of Science