title: Functionalization of methyl orange using cationic peptide amphiphile: colorimetric discrimination between ATP and ADP at pH 2.0.
abstract: A solvatochromic and non-fluorescent acid-base indicator, methyl orange (MO) was applied to colorimetric discrimination between adenosine triphosphate (ATP) and the corresponding diphosphate (ADP) at pH 2.0 in the presence of L-glutamic acid-derived cationic peptide amphiphile 1. This method is based on the fact that the amphiphile 1 can prevent MO from protonation even at pH 2.0. No similar colour change was observed when ADP was added instead of ATP under the same conditions. The effect of the molecular structure of several peptide amphiphiles and dyes was also investigated.
authors.affiliation: Division of Applied Chemistry, Graduate School of Engineering, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Ryu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hachisako
mesh_terms: D000244:Adenosine Diphosphate / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D003124:Colorimetry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D002412:Cations; D010455:Peptides; D013501:Surface-Active Agents; D000244:Adenosine Diphosphate; C100258:methyl orange; D000255:Adenosine Triphosphate