title: Supramolecular structures generated by a p-tert-butylphenylamide derivative of deoxycholic acid. From planar sheets to tubular structures through helical ribbons.
abstract: The formation of supramolecular structures initiated by a p-tert-butylphenylamide derivative of deoxycholic acid (Na-t-butPhDC) is investigated. At 1.18 mM concentration of Na-t-butPhDC and 37 degrees C, initial flat ribbons are observed which self-transform into helical ribbons (with a mean pitch angle of 47 +/- 6 degrees) which finally originate molecular tubes with an external diameter of 241 +/- 28 nm. Most of the molecular tubes show helical markings with a pitch angle value of 45 +/- 4 degrees, in full agreement with predictions of simple models based on chiral elastic properties of the membrane. A lateral association mechanism is proposed to account for the growth of the external diameter (from 225 +/- 32 to 546 +/- 59 nm) of tubes with time at 3.99 mM.
authors.affiliation: Departamento de Química Física, Facultad de Ciencias, Universidad de Santiago de Compostela, Avda. Alfonso X El Sabio s/n, 27002 Lugo, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Meijide
authors.forename: Alvaro
authors.initials: A
authors.lastname: Antelo
authors.forename: Mercedes
authors.initials: M
authors.lastname: Alvarez Alcalde
authors.forename: Aida
authors.initials: A
authors.lastname: Jover
authors.forename: Luciano
authors.initials: L
authors.lastname: Galantini
authors.forename: Nicolae Viorel
authors.initials: NV
authors.lastname: Pavel
authors.forename: José
authors.initials: J
authors.lastname: Vázquez Tato