Code: WOB	Time Slot/Poster Number: 10:30 - 11:00 am	Session: Resonance Raman in Biological Systems II
UV Resonance Raman Investigations of Peptide/Protein Conformation and Folding
Sandy Asher; Bhavya Sharma; Lu Ma; Sergei Bykov; Nataliya Myshakina; Zhenmin Hong; Kan Xiong
University of Pittsburgh, Pittsburgh, PA
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Summary
Our investigations of UV resonance Raman spectroscopy (UVRR) of peptides and proteins has given us insight into their electronic transitions as well as into the dependence of their biomolecular conformations on their solution environments.

Code: WOB	Time Slot/Poster Number: 11:00 - 11:30 am	Session: Resonance Raman in Biological Systems II
Tryptophan Residues as Membrane Protein Anchors
Judy Kim; Diana Schlamadingerd; Hannah Shafaat; Katie Sanchez; Jonathan Gable
UC San Diego, La Jolla, CA
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Summary
Tryptophan is unique among the natural amino acids; for example, it exhibits the largest accessible nonpolar surface area, has the greatest ionization potential, possesses an indole N-H moiety for hydrogen bond donation, and displays the greatest electrostatic potential for cation-pi interactions. These important chemical properties render tryptophan an important functional residue in diverse biological systems. Our group utilizes resonance Raman and electronic spectroscopy to probe the photophysical, photochemical, and structural properties of tryptophan in two broad themes in biology: electron transfer chemistry and membrane proteins. Here, we focus on the topic of membrane protein folding and membrane-associated peptides.

Code: WOB	Time Slot/Poster Number: 11:30 am - 12:00 pm	Session: Resonance Raman in Biological Systems II
Amyloid Fibrils are “Alive” as Evident from Deep UV Raman Spectroscopic Examination: an Instrumentation Driven Discovery
Igor Lednev; William Lauro; Dmitry Kurouski
SUNY at Albany, Albany, NY
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Summary
Mature fibrils prepared from apo-α-lactalbumin spontaneously refold from one polymorph to another as a result of a mild alteration in solution temperature and salinity. The refolding process occurs without fiber disintegration and the fibril core remains protected from the solvent despite a substantial β-sheet melting and reforming. This discovery changes the very concept of the extraordinary stability of amyloid fibrils and presages a new approach for potentially regulating the biological activity of fibrils and their associated toxicity.

Code: WOB	Time Slot/Poster Number: 12:00 - 12:20 pm	Session: Resonance Raman in Biological Systems II
Resonance Raman Spectroscopy of Helical Porphyrin Nanotubes: Hierarchal Structure and Exciton Coupling
Benjamin Friesen; Christopher Rich; Ursula Mazur; Jeanne Mchale
Washington State University, Pullman, WA
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Summary
Polarized resonance Raman spectra are presented for helical nanotubes of tetra-(sulfonatophenyl)porphyrin in solution and adsorbed on Au(111). When excited within the red-shifted component of the Soret band (J band), the intensities of strongly-enhanced low-frequency modes reveal components of the transition moment parallel and perpendicular to the nanotube axis. Exciton theory based on structural data from scanning tunneling microscopy results in good agreement with optical and resonance Raman data and reveals the hierarchy of transition dipole coupling within and among the 6 nm disks from which the nanotubes are assembled.

Code: WOB	Time Slot/Poster Number: 12:20 - 12:40 pm	Session: Resonance Raman in Biological Systems II
Comparative Studies of Therapeutic Protein Secondary Structure Using Deep UV Resonance Raman Spectroscopy
Sergey Arzhantsev; Connie Ruzicka; John Kauffman
US Food and Drug Administration, Saint Louis, MO
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Summary
Protein secondary structure has the potential to influence the biological and immunological efficacy and potency of therapeutic proteins. Deep UV resonance Raman spectroscopy sensitive to protein secondary structure, because the ~200 nm excitation source is resonant with protein amide electronic transitions, and vibronic coupling preferentially enhances the Raman cross section of the protein backbone vibrational modes. Studies on insulin, insulin variants and aggregated insulin using DUV resonance Raman spectroscopy will be presented.