title: Spontaneous Pulsation of Peptide Microstructures in an Abiotic Liquid System.
abstract: We report observations of pulsating peptide formation and depeptidization in 70% aqueous acetonitrile solutions of l-Pro-l-Phe and l-Cys, resulting in the oscillatory appearance and disappearance of solid masses of microfibers and microspheres, respectively. We monitor the concentration changes of the monomeric amino acids by high-performance liquid chromatography. The concentration of all amino acid solutions used is 1.0 mg mL(-1), due to solubility limitations in 70% aqueous acetonitrile. The nonlinear concentration changes of l-Pro, l-Phe and l-Cys, and the amounts of the main peptidization products observed within our monitoring periods (for l-Pro-l-Phe, 250 h, and for l-Cys, 70 h) are typically from several to 20% of the original monomer concentrations. We follow the formation and decay of the insoluble peptides by turbidimetry. We also investigate the materials formed using scanning electron microscopy and mass spectrometry. We carry out numerical simulations on a simple model that reflects the main features of spontaneous pulsation of peptide fiber or sphere formation in this abiotic liquid system.
authors.affiliation: Department of General Chemistry and Chromatography, Institute of Chemistry, University of Silesia, 9 Szkolna Street, Katowice, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Maciejowska
authors.affiliation: Department of General Chemistry and Chromatography, Institute of Chemistry, University of Silesia, 9 Szkolna Street, Katowice, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Godziek
authors.affiliation: Department of Physics of Crystals, University of Silesia, 4 Uniwersytecka Street, 40-007 Katowice, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Talik
authors.affiliation: Department of General Chemistry and Chromatography, Institute of Chemistry, University of Silesia, 9 Szkolna Street, Katowice, Poland.
authors.forename: Mieczysław
authors.initials: M
authors.lastname: Sajewicz
authors.affiliation: Department of General Chemistry and Chromatography, Institute of Chemistry, University of Silesia, 9 Szkolna Street, Katowice, Poland teresa.kowalska@us.edu.pl.
authors.forename: Teresa
authors.initials: T
authors.lastname: Kowalska
authors.affiliation: Department of Chemistry, Brandeis University, MS 015, Waltham, MA 02454-9110, USA.
authors.forename: Irving R
authors.initials: IR
authors.lastname: Epstein
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D003198:Computer Simulation; D013058:Mass Spectrometry; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D010455:Peptides / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D000596:Amino Acids; D010455:Peptides; D014867:Water; C032159:acetonitrile