title: Polyisocyanides derived from tripeptides of alanine.
abstract: Helical polymers of isocyanotripeptides derived from alanine have been synthesized and their architectures studied in detail. The helical conformation of the polyisocyanotripeptides is stabilized by internal hydrogen-bonding arrays between the tripeptide side chains. The possibility of extending the well-defined hydrogen-bonded array, from dipeptide to tripeptide side chains, depends strongly on the stereochemistry of the constituent alanine amino acids, as has been shown by circular dichroism and IR studies. In polymers containing a weaker hydrogen-bonding array adjacent to the polymer backbone, due to steric interactions between the alanine methyl groups, a stronger second hydrogen-bonding array was present between the peptide bonds furthest away from the main chain, which is probably a result of stretching/compression of the helical-polymer conformation.
authors.affiliation: Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Metselaar
authors.forename: P J Hans M
authors.initials: PJ
authors.lastname: Adams
authors.forename: Roeland J M
authors.initials: RJ
authors.lastname: Nolte
authors.forename: Jeroen J L M
authors.initials: JJ
authors.lastname: Cornelissen
authors.forename: Alan E
authors.initials: AE
authors.lastname: Rowan
mesh_terms: D000409:Alanine / Q000737:chemistry*; D002384:Catalysis; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D008958:Models, Molecular; D008968:Molecular Conformation; D009532:Nickel / Q000737:chemistry; D009570:Nitriles / Q000138:chemical synthesis* / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D012015:Reference Standards; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods
chemical_list: D009570:Nitriles; D009842:Oligopeptides; D009532:Nickel; D000409:Alanine