Code: MP25	Time Slot/Poster Number: 048	Session: Molecular Biophysics and Photobiology I
Density Functional Study and Intramolecular Charge Transfer from the Vibrational Spectra of 1- (4-aminophenyl) 3-(3, 4 – dimethoxyphenyl)-2-propen-1- one
D. Sajan ; Lynnette Joseph ; I. Hubert Joe
University of Kerala, Trivandrum, India
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Summary
NIR-FT Raman and FT-IR spectral analysis of 1-(4-Aminophenyl)-3-(3,4-dimethoxyphenyl)-prop-2-en-1-one, a bioactive molecule, is carried out along with ab initio computations. Analysis of phenyl ring modes shows that the ADPP stretching mode 8 and the aromatic C–H in-plane bending mode are equally active as strong bands in both IR and Raman spectra, which can be interpreted as the evidence of intramolecular charge transfer (ICT) between the donor and acceptor groups via conjugated ring path and is responsible for bioactivity of the molecule.

Code: MP25	Time Slot/Poster Number: 049	Session: Molecular Biophysics and Photobiology I
FT-IR and FT-Raman spectra of complex of La(III) with 6-aminouracil
Hitesh Kumar1; BK Rai1; Meenakshi Sharma1; MA Palafox2; RK Soni1; V.K. Rastogi1
1C.C.S University, Meerut, India; 2Departmento de Quimica Physica I, Facultad de Cie, Madrid, Spain
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Summary
FT-IR and FT-Raman spectra of La(III) with 6-aminouracil have been recorded and analyzed. . The analysis of vibrational spectra shows the presence of the ketonic form of the Ligand (6-aminouracil) in the solid state with the presence of NH stretching band and the absence of OH stretching. The bands due to N-H modes almost remain unaltered suggesting that these groups are not involved in complexation.

Code: MP25	Time Slot/Poster Number: 050	Session: Molecular Biophysics and Photobiology I
Raman and Infrared Spectra of Hydrated 2,4-Dithiouracil Molecule
V.K. Rastogi; Alcolea Palafox; A. Guerrero-Martínez; G. Tardajos; J.K. Vats; Rashmi Tomer
Professor, Madrid, Spain
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Summary
2,4-dithiouracil offers special importance by its role in anticancer and antiviral activity. However, little attention has been paid on the effect of the water on the Infrared and Raman spectra of this molecule. The influence of the water was mainly considered including a variable number of explicit water molecules until seven surrounding 2,4-dithiouracil. The simulation of the spectra was carried out by using B3LYP/6-31G** basis set implemented in the GAUSSIAN 03 program package. Several general conclusions were underlined.

Code: MP25	Time Slot/Poster Number: 051	Session: Molecular Biophysics and Photobiology I
Raman-Spectroscopic Study of L-Alanine Single Crystals in the Temperature Range of 3-300 K
Boris Kolesov
Novosibirsk, Russian Federation
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Summary
The polarized Raman spectra of the oriented single crystals of L-alanine have been studied at 3-300 K. The low-wavenumber band at 41 cm-1 and regularly spaced band packets in the range 2500-3000 cm-1 are assigned to N∙∙∙O and N-H self-trapped states respectively both mediated by zero point quantum motions. The analysis of wavenumber, bandwidth and Raman intensity of all modes polarized along c-axis in the range 100-600 cm-1 results in an assumption on existence in L-alanine single-crystals of temperature instability of intermolecular interactions and micro-conformational phase transitions accompanied by the rearrangement of the hydrogen bond’s network.

Code: MP25	Time Slot/Poster Number: 052	Session: Molecular Biophysics and Photobiology I
Structural Refinement of a Key Tryptophan Residue in the BLUF Photoreceptor AppA by Ultraviolet Resonance Raman Spectroscopy
Masashi Unno1, 3; Sadato Kikuchi1; Shinji Masuda2, 3
1Saga University, Saga, Japan; 2Tokyo Institute of Technology, Yokohama, Japan; 3JST, Kawaguchi, Japan
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Summary
The flavin-adenine-dinucleotide-binding BLUF domain constitutes a new class of blue-light receptors, and the N-terminal domain of AppA is a representative of this family. Recently, crystal and solution structures of several BLUF domains were obtained, and their overall structures are consistent. However, there is a key ambiguity regarding the position of a conserved tryptophan, i.e., this residue was found either close to flavin or exposed to the solvent. In this study, we examine the Trp conformation for the BLUF domain of AppA through a direct observation of the vibrational spectrum of Trp104 by ultraviolet resonance Raman spectroscopy.

Code: MP25	Time Slot/Poster Number: 053	Session: Molecular Biophysics and Photobiology I
Natural Bond orbital Analysis and Vibrational Spectral Investigation of 3,5-(Dinitro benzoic acid)
V.K. Rastogi2; M. Amalanathan1; I. Hubert Joe1
1University of Kerala, Trivandrum, India; 2C.C.S University, MEERUT, INDIA
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Summary
NIR FT-Raman and FT-IR spectra of the material 3,5-Dinitrobenzoic acid have been recorded and analyzed. The spectral interpretation has been done following full structure optimization and vibrational wavenumbers calculated on based on the density functional theory. The calculated optimized geometrical parameters and the vibrational wavenumbers well agreement with the experimental values. The possible hyperconjugative interaction are confirmed using natural bond orbital analysis.

Code: MP25	Time Slot/Poster Number: 054	Session: Molecular Biophysics and Photobiology I
Spectroscopic Study of Magnesium Effect on Stability of RNA and DNA Triple Strand Polynucleotide Structures
Shirly Josefina Espinoza Herrera; Ivan Barvik Jr.; Josef Stepanek
Institute of Physics. Charles University in Prague, Prague, Czech Republic
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Summary
Using spectroscopic Raman titration, the spectral patterns of the magnesium interaction with single strands, duplexes and triplexes form by PolyA and PolyU were obtained. The magnesium ion interacts through inner-sphere with the keto-oxygen of the pyrimidine and also changes the torsional angles on the surrounding sugar phosphate backbones. There is one Mg2+ ion per 2 triads of PolyU.PolyA.PolyU triplex. The results obtained by Raman spectroscopy were confirmed by Molecular Dynamics Simulations where Magnesium appears specifically localized in pockets distributed along the triplex chain and close to the bases of PolyA and Hoogsteen (the third) PolyU strand.

Code: MP25	Time Slot/Poster Number: 055	Session: Molecular Biophysics and Photobiology I
Raman Scattering Study of Ligand-Binding Interactions in SOUL Protein Single Crystals
Barbara Rossi1; Marco Giarola1; Gino Mariotto1; Emmanuele Ambrosi2; Hugo L. Monaco2
1Dep. of Computer Science, University of Verona, Verona, Italy; 2Dep. of Biotechnology, Unversity of Verona, Verona, Italy
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Summary
SOUL is a recently discovered protein found in many organisms, including humans, believed to be involved in the binding and transport of heme and porphyrins. The functional studies on this protein are not numerous and, at present, the role and the specific physiological function of SOUL in the cell are still far from being fully clarified, as well as its 3-D structure is not well refined. Here, micro-Raman spectroscopy is used to study the vibrational properties of single crystals of pure SOUL protein and crystals soaked with suitable small molecules, in order obtain information on the chemistry of ligand-protein interactions.

Code: MP25	Time Slot/Poster Number: 056	Session: Molecular Biophysics and Photobiology I
Raman Study of Mutarotation Process in Aqueous Solutions of Glucose
Oleksandr Slobodyanyuk
Department of Physics, Taras Shevchenko National U, Kyiv, Ukraine
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Summary
Raman spectra of aqueous solution (H2O, its anolyte and catolyte, and D2O) of glucose were measured at different stages of mutarotation process. Some Raman peaks in spectra of glucose in D2O solution are shifted in respect to corresponding peaks in H2O solution. Considerable change of rate of mutarotation in catolyte and anolyte of glucose solutions is accompanied by change of relative Raman peaks intensity without noticeable shifts of their position in the spectra. This fact may be considered as evidence of the major contribution of deuteration into above mentioned shifts of Raman peaks.

Code: MP25	Time Slot/Poster Number: 057	Session: Molecular Biophysics and Photobiology I
Raman Spectroscopic Studies of Structural Changes of Insulin in Controlled Fluid Flows
Jonathan Dusting1; Grant Webster2; Ewan W Blanch2; Stavroula Balabani1
1King's College London, London, United Kingdom; 2University of Manchester, Manchester, United Kingdom
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Summary
Stresses inherent to viscous fluid flow have previously been associated with protein unfolding, although structural changes have not been well documented as a function of relevant hydrodynamic parameters. We have used Raman Spectroscopy to monitor the structure of insulin for multiple flow scenarios within a concentric cylinder flow cells. Under high-stress flow conditions, protein spectra differ significantly compared to those acquired under stationary conditions, and indicate strcutral changes including a variation in protein helicity. However under low-stress conditions the spectra are extremely consistent, implying that there is a mechanical stress threshold for flow-induced structural changes.

Code: MP25	Time Slot/Poster Number: 058	Session: Molecular Biophysics and Photobiology I
Hydrogen bond analysis of L-Ascorbic acid: ab initio study
V.K. Rastogi1; Padam Kumar1; Rashmi Tomer1; M. Alcolea Palafox2; I. Hubert Joe3
1C.C.S University, Meerut, India; 2Departamento de Química-Física I (Espectroscopía), Madrid, Spain; 3University of kerala, Trivandrum, India
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Summary
Hydrogen bonds are currently one of the main fields of hydrogen bonding research both experimentally and theoretically and these types of hydrogen bonding play a key role in structure and activity of the molecule. The vibrational spectra and the hydrogen bond geometry analysis of L-Ascorbic acid were carries out using Density Functional Theory calculation. The Lowering of OH stretching wavenumber confirm the O-H…O hydrogen bond.

Code: MP25	Time Slot/Poster Number: 059	Session: Molecular Biophysics and Photobiology I
Resonance Raman Study of the PH Dependence of Poly-L-lysine Conformations
Lu Ma; Sanford Asher
University of Pittsburgh, Pittsburgh, PA
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Summary
We used 204 nm excitation UV Resonance Raman spectroscopy to examine the pH dependence of the conformations of poly-L-lysine (PLL). We found that more than two states are involved in the conformational transitions of PLL induced by increasing the pH from 7.1 to 11.7, whereas the transitions between pH 9.1 to 11.7 involve only two states.

Code: MP25	Time Slot/Poster Number: 060	Session: Molecular Biophysics and Photobiology I
The Application of Raman Microscopy in Drug Design and Drug Screening
Jingjing Shou
Case Western Reserve University, Cleveland, Ohio
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Summary
Raman microscopy is proving an invaluable tool to characterize interactions between drug compounds and their target enzymes. Commonly, drug candidates are infused into single crystals of the enzyme and chemical changes in the active site are monitored using a Raman microscope and difference spectroscopy. The application of Raman microscopy improves the drug design and drug screening.

Code: MP25	Time Slot/Poster Number: 061	Session: Molecular Biophysics and Photobiology I
Confocal Raman Study on Dehydration Process of Insulin Crystals
Guang Zeng; Kaikai Li; Yunhong Zhang
The Institute for Chemical Physics, Beijing instit, Beijing, China
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Summary
By means of the conventional hanging drop vapor diffusion meathod, high quality insulin crystals were obtained. Taking advantage of confocal Raman spectroscopy, we investiged the dehydration process of insulin crytals. Three steps were observed for this process, which may reveal that there could be three kinds of hydration water in insulin crystals.

Code: MP25	Time Slot/Poster Number: 062	Session: Molecular Biophysics and Photobiology I
Inter-residue Coupling of Model PPII Helices Using 13C Isotopic Labeling Investigated by Vibrational Spectroscopy
Chi Heng; Ahmed Lakhani; Anjan Roy; Marcelo Nakaema; Timothy A. Keiderling
University of Illinois at Chicago, Chicago, IL
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Summary
Coupling of selected residues for a series of related peptides having predominantly PPII conformations were measured using Raman scattering, VCD and IR spectra of selected variants that were doubly labeled with 13C on the amide C=O. The characteristics of the 13C=O component of the amide I’ IR band and their sensitivity to the local structure of the peptide are compared to predictions based on DFT level calculations for related structures and used to determine coupling between C=O groups along the backbone of this helical structure.

Code: MP25	Time Slot/Poster Number: 063	Session: Molecular Biophysics and Photobiology I
Comprehensive Description of Heme Iron Dynamics From X-ray Vibrational Spectroscopy
J. Timothy Sage
Northeastern University, Boston, MA
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Summary
Nuclear resonance vibrational spectroscopy (NRVS) reveals the vibrational dynamics of a Mössbauer probe nucleus. Here, 57Fe NRVS measurements yield the complete spectrum of Fe vibrations in halide complexes of iron porphyrins. Iron porphine serves as a useful comparison with the more complex spectrum of less symmetric heme molecules that contribute to numerous essential biological processes.