title: A fluorescent peptoid pH-sensor.
abstract: Peptoids, N-substituted glycine oligomers, can adopt stable three-dimensional structures and have found diverse application as peptide surrogates and as nanomaterials. In this report, we have expanded peptoid function to include pH sensing by coupling pH-induced peptoid conformational changes with fluorescence intensity changes. We report two new peptoids (2 and 3) that comprise carboxylic-acid functionalized side chains and undergo conformational rearrangement in response to pH. Peptoids 2 and 3 are also labeled at one side-chain with an environmentally sensitive fluorophore, 4-N,N-dimethylamino-1,8-naphthalimide (4DMN). The fluorescence intensity of 2 varies 24-fold over the pH range studied. These spectroscopic properties make 2 a sensitive, biocompatible pH sensor.
authors.affiliation: Department of Chemistry & Biochemistry, Santa Clara University, 500 El Camino Real, Santa Clara, CA, 95053.
authors.forename: Amelia A
authors.initials: AA
authors.lastname: Fuller
authors.forename: Courtney A
authors.initials: CA
authors.lastname: Holmes
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Seidl
mesh_terms: D005998:Glycine / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D034444:Peptoids / Q000737:chemistry; D017433:Protein Structure, Secondary
chemical_list: D010455:Peptides; D034444:Peptoids; D005998:Glycine
keywords: conformational rearrangement; environmentally sensitive fluorophore; peptidomimetic; peptoid oligomer