title: Number of solution states of bradykinin from ion mobility and mass spectrometry measurements.
abstract: Ion mobility and mass spectrometry measurements have been used to examine the populations of different solution structures of the nonapeptide bradykinin. Over the range of solution compositions studied, from 0:100 to 100:0 methanol:water and 0:100 to 90:10 dioxane:water, evidence for 10 independent populations of bradykinin structures in solution is found. In some solutions as many as eight structures may coexist. The solution populations are substantially different than the gas-phase equilibrium distribution of ions, which exhibits only three distinct states. Such a large number of coexisting structures explains the inability of traditional methods of characterization such as nuclear magnetic resonance spectroscopy and crystallography to determine detailed structural features for some regions of this peptide.
authors.affiliation: Department of Chemistry, Indiana University, Bloomington, 47405, United States.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Pierson
authors.forename: Liuxi
authors.initials: L
authors.lastname: Chen
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Valentine
authors.forename: David H
authors.initials: DH
authors.lastname: Russell
authors.forename: David E
authors.initials: DE
authors.lastname: Clemmer
mesh_terms: D001920:Bradykinin / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D008958:Models, Molecular; D014665:Vasodilator Agents / Q000737:chemistry*
chemical_list: D007477:Ions; D014665:Vasodilator Agents; D001920:Bradykinin