eprintid: 17215 rev_number: 26 userid: 1419 dir: disk0/00/01/72/15 datestamp: 2013-02-08 21:11:48 lastmod: 2021-06-12 23:55:33 status_changed: 2013-02-08 21:11:48 type: article metadata_visibility: show item_issues_count: 0 eprint_status: archive creators_name: Ahmed, Z creators_name: Asher, SA creators_email: creators_email: asher@pitt.edu creators_id: creators_id: ASHER title: UV resonance Raman investigation of a 310-helical peptide reveals a rough energy landscape ispublished: pub divisions: sch_as_chemistry full_text_status: public abstract: We used UVRRS at 194 and 204 nm excitation to examine the backbone conformation of a 13-residue polypeptide (gp41659-671) that has been shown by NMR to predominantly fold into a 310-helix. Examination of the conformation sensitive AmIII3 region indicates the peptide has significant populations of β-turn, PPII, 310-helix, and π-helix-like conformations but little α-helix. We estimate that at 1 °C on average six of the 12 peptide bonds are in folded conformations (predominantly 310- and π-helix), while the other six are in unfolded (β-turn/PPII) conformations. The folded and unfolded populations do not change significantly as the temperature is increased from 1 to 60 °C, suggesting a unique energy landscape where the folded and unfolded conformations are essentially degenerate in energy and exhibit identical temperature dependences. © 2006 American Chemical Society. date: 2006-08-01 date_type: published publication: Biochemistry volume: 45 number: 30 pagerange: 9068 - 9073 refereed: TRUE issn: 0006-2960 id_number: 10.1021/bi060858m pmid: 16866352 mesh_headings: HIV Envelope Protein gp41--chemistry mesh_headings: Peptide Fragments--chemistry mesh_headings: Protein Conformation mesh_headings: Protein Structure, Secondary mesh_headings: Spectrophotometry, Ultraviolet--methods mesh_headings: Spectrum Analysis, Raman--methods mesh_headings: Temperature mesh_headings: Thermodynamics chemical_names: HIV Envelope Protein gp41 chemical_names: Peptide Fragments citation: Ahmed, Z and Asher, SA (2006) UV resonance Raman investigation of a 310-helical peptide reveals a rough energy landscape. Biochemistry, 45 (30). 9068 - 9073. ISSN 0006-2960 document_url: http://d-scholarship-dev.library.pitt.edu/17215/1/licence.txt