title: Effects of proline ring conformation on theoretical pi-pi* absorption and CD spectra of helical poly(L-proline) forms I and II.
abstract: Absorption and CD spectra of the pi-pi* transition near 200 nm are calculated for helical (Pro)10 forms I and II with a variable proline ring conformation characterized by torsion angle chi 2 in the range -60 degrees to 60 degrees. The spectra for poly(Pro) I are not sufficiently sensitive to chi 2 to suggest a preferred ring conformation. The spectra for poly(Pro) II are more sensitive to chi 2, and suggest preferred ring conformations near either or both of the chi 2 regions -50 +/- 10 degrees and 50 +/- 10 degrees.
authors.affiliation: Department of Chemistry, Iowa State University, Ames 50011.
authors.forename: K A
authors.initials: KA
authors.lastname: Thomasson
authors.forename: J
authors.initials: J
authors.lastname: Applequist
mesh_terms: D002942:Circular Dichroism; D010455:Peptides / Q000737:chemistry*; D011392:Proline / Q000737:chemistry*; D011487:Protein Conformation; D013057:Spectrum Analysis
chemical_list: D010455:Peptides; C011083:polyproline; D011392:Proline