title: Factors Affecting the Stabilization of Polyproline II Helices in a Hydrophobic Environment.
abstract: Several parameters have a critical importance for the stabilization of either polyproline I (PPI) or polyproline II (PPII) helices in a hydrophobic environment. Among them, it was found out that the concentration is crucial as polyprolines at 3 mM concentration stably fold in PPII helices, that are organized in aggregates stable even after several days and are detectable by dynamic light scattering analysis. In more diluted concentration the same molecules stably fold in PPI helices, and no aggregates are found. In contrast, the introduction of a (4S,5R)-4-carboxy-5-methyloxazolidin-2-one (L-Oxd) moiety always inhibits the formation of the PPI helix, regardless of the L-Oxd position and the solution concentration.
authors.affiliation: Dipartimento di Chimica Ciamician, Università di Bologna , Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Zanna
authors.affiliation: Dipartimento di Chimica Ciamician, Università di Bologna , Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Milli
authors.affiliation: Dipartimento di Chimica Ciamician, Università di Bologna , Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Del Secco
authors.affiliation: Dipartimento di Chimica Ciamician, Università di Bologna , Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Tomasini
mesh_terms: D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D023303:Oxazolidinones / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary
chemical_list: C000610073:4-carboxy-5-methyloxazolidin-2-one; D023303:Oxazolidinones; D010455:Peptides; C011083:polyproline