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TP15

Code: TP15	Time Slot/Poster Number: 115	Session: Raman Optical Activity
Observation Of Resonance Electronic And Non-Resonance Enhanced Vibrational Natural Raman Optical Activity
Christian Merten¹; Honggang Li²; Xuefang Lu²; Andreas Hartwig¹; Laurence A. Nafie^{2, 3}
¹Fraunhofer Institute for Manufactoring Technology, Bremen, Germany; ²BioTools, Inc., Jupiter, FL; ³Department of Chemistry, Syracuse University, Syracuse, NY

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Summary
Natural resonance electronic Raman optical activity (ROA) is observed for the first time. Coincidently, the first example of vibrational ROA enhanced by low-lying electronic transition is reported. These new phenomena were measured using the rare-earth complex Eu(tfc)3 [tris(3-trifluoromethylhydroxymethylene d-camphorate)]europium(III) where electronic resonance occurs between the 532-nm laser excitation and the 7F1-5D1 transition of the Eu3+ metal center. Electronic Raman spectra involve Raman transitions terminating on low-lying electronic states of Eu(tfc)3. The observed vibrational ROA spectra are enhanced relative to typical ROA spectra by proximity of vibrational states of Eu(tfc)3 to its low-lying electronic states.

Code: TP15	Time Slot/Poster Number: 116	Session: Raman Optical Activity
Using Machine Learning to Predict Protein Structure from Spectral Data
Myra Kinalwa¹; Andrew Doig³; Ewan. W. Blanch²
¹PhD Student, Manchester, United Kingdom; ²Senior Lecturer, Manchester, United Kingdom; ³Professor, Manchester, United Kingdom

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Summary
This paper presents chemometric analysis of ROA and Raman data to identify SCOP fold classes and structural content. Machine learning techniques such as SVM Classification and SVM Regression were employed. In addition to these PLS Regression and Random Forest clustering were used to invesigate the relation of spectral features to protein secondary and tertiary structure.

Code: TP15	Time Slot/Poster Number: 117	Session: Raman Optical Activity
An Experimental And Theoretical Raman and ROA Study Of α- and β-N-acetyl-L-Asp-L-Glu, L-Asp-L-Glu And Their Derivatives: N-acetyl-L-Asp, N-acetyl-L-Glu.
Clare Levene¹; Saeideh Ostovar pour¹; Trevor Dines²; Nighat Kausar³; Babur Chowdhry⁵; Ewan Blanch⁴
¹PhD student, Manchester, United Kingdom; ²Scientific Researcher, Dundee, Scotland; ³Research Scientist, Kent, UK; ⁴Senior Lecturer, Manchester, UK; ⁵Professor, Kent, UK

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Summary
An investigaton into the solution structure of glutamate and aspartate containing DAAPs. α-NAAG has been extensively researched as an excitory neurotransmitter, anti-histamine, mass cell de-granulator while β-NAAG has been implicated in neuropsychiatric disorders, N-acetyl-L-Asp and N-acetyl-L-Glu are neurotransmitters in the brain. α-NAAG and β-NAAG are constitutional isomers that display very similar Raman spectrum, however, the bands observed in the ROA spectra for both isomers display differences in the 1200 - 1800 cm-1 region which is sensitive to secondary structure.

Code: TP15	Time Slot/Poster Number: 118	Session: Raman Optical Activity
Flexibility of Paramagnetic (d1) Organometallic Dithiolene Complexes [Cp2M(dmit)]+. (M = Mo, W) Studied by Raman Spectroscopy
Andrzej Lapinski¹; Roman Swietlik¹; Iwona Olejniczak¹; Damian Lazarski¹; Marc Fourmigue²; Eric W. Reinheimer²; Olivier Jeannin²; Kyuya Yakushi³
¹Institute of Molecular Physics PAS, Poznan, Poland; ²Sciences Chimiques de Rennes, Universite de Rennes, 35042 Rennes, France; ³Institute for Molecular Science, Myodaiji, Okazaki, Japan

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Summary
The radical cation salts of the Cp_2M(dmit) complexes (where M = Mo,W) have been obtained and structurally characterized with a variety of anions. From the crystallographic investigations it was shown that the folding angle of cations is strongly dependent on the counter ion and the crystal structure. The complex folding is associated with a shift of charge density, what has an influence on their vibrational spectra. In this work, we show that vibrational spectroscopy can be applied for investigation of complex deformations in the solid state.

Code: TP15	Time Slot/Poster Number: 119	Session: Raman Optical Activity
Raman Optical Activity of Amide and Disulphide Groups in Peptides and Model Systems
Vladimir Baumruk
Charles University in Prague, Faculty of Mathemati, Prague 2, Czech Republic

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Summary
The aim of this work was to determine the relationship between three-dimensional structure and Raman optical activity of disulphide and amide groups in peptides. Characteristic band patterns of the polyproline II conformation were found in the ROA spectra of poly(Pro-Gly-Pro), oxytocin and hinge peptide linked to the antigen sequence. ROA signal in the S-S and C-S stretching region was observed in ROA spectra of model cyclodextrin compounds connected with disulphide bonds. Positive ROA band in the S-S stretching region was found in the ROA spectrum of oxytocin. Positive ROA signal in this region indicates positive dihedral angle Cβ-S-S-Cβ.

Code: TP15	Time Slot/Poster Number: 120	Session: Raman Optical Activity
Study on Denaturation of Bovine α-Lactalbumin by Raman, Raman Optical Activity, and IR Spectroscopy
S. R. Ryu¹; M. K. Kim¹; B. Czarnik-Matusewicz²; L. A. Lafie^{3, 4}; R. K. Dukor⁴; Y. M. Jung¹
¹Kangwon National University, Chuncheon, Korea; ²University of Wroclaw, Wroclaw, Poland; ³Syracuse University, Syracuse, USA; ⁴BioTools Inc., Jupiter, USA

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Summary
Raman optical activity (ROA) refers to a small difference in the intensity of the right and left circularly polarized states of the scattered light by the most rigid and chiral parts of the structure in analyzed molecules. Two-dimensional correlation spectroscopy (2DCOS) has attracted a high level of interest of analytical science community, as it provides considerable utility and benefit in many fields of spectroscopic studies. In this study, we have applied 2D correlation spectroscopy to IR and ROA spectra of the pH-dependent bovine α-lactalbumin to investigate the molten globule state.

Code: TP15	Time Slot/Poster Number: 121	Session: Raman Optical Activity
Size and Wall Thickness Effects of Plasmonic Metal Nanobowl Structures
Yun Ma ; Zexiang Shen
Nanyang Technological University, Singapore, Singapore

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Summary
Plasmonic metal nanobowl structure is an attractive research topic because their optical properties can be tuned by the bowl size, wall thickness, material species and interspacing between two nearest bowls. The photo emission observed from both Ag and Au nanobowl structures indicates the excitation of surface plasmon resonance (SPR) under the illumination of green laser (532 nm). Au nanobowl arrays exhibits different electromagnetic enhancement (EME) orientation dependence on the incident laser polarization with different bowl sizes. Simulation results show wall thickness is an effective factor to tune plasmonic resonance of metal nanobowl structure.

Code: TP15	Time Slot/Poster Number: 122	Session: Raman Optical Activity
Structural Analysis of Valinomycin in Solution Studied by Raman Optical Activity
Shigeki Yamamoto^{1, 2}; Michal Straka²; Hitoshi Watarai¹; Petr Bouř²
¹Osaka University, Osaka, Japan; ²IOCB, Prague, Czech Republic

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Summary
Detailed structures of valinomycin molecule in methanol solution were studied by means of Raman optical activity (ROA) spectroscopy. The experimental spectra were interpreted by first principles computations.

Code: TP15	Time Slot/Poster Number: 124	Session: Raman Optical Activity
Experimental And Computational Raman And ROA Studies Of Cyclic And Linear Forms Of L-Ser-L-Ser And L-Ala-L-Ala
Saeideh Ostovar Pour; Clare Levene
PhD student, Manchester, United Kingdom

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Summary
Raman and Raman optical activity have been utilized to determine peptide conformation in solution as a result of their sensitivity to molecular conformation. Short dipeptides such as diketopiperazine (DKP) have been investigated during the last few decades for both natural and synthetic, since they are involve in a wide variety of biological activities including anti-tumour, anti-viral and anti-bacterial activities. DFT calculations were carried out in order to compute Raman and ROA spectra for both linear and cyclic dipeptides. Experimental and calculated Raman and ROA spectra of cyclic and linear L-Ser-L-Ser and L-Ala-L-Ala have been compared.