Monolayer Sensitivity Enables a 2D IR Spectroscopic Immuno-biosensor for Studying Protein Structures: Application to Amyloid Polymorphs.

ABSTRACT: Immunosensors use antibodies to detect and quantify biomarkers of disease, though the sensors often lack structural information. We create a surface-sensitive two-dimensional infrared (2D IR) spectroscopic immunosensor for studying protein structures. We tether antibodies to a plasmonic surface, flow over a solution of amyloid proteins, and measure the 2D IR spectra. The 2D IR spectra provide a global assessment of antigen structure, and isotopically labeled proteins give residue-specific structural information. We report the 2D IR spectra of fibrils and monomers using a polyclonal antibody that targets human islet amyloid polypeptide (hIAPP). We observe two fibrillar polymorphs differing in their structure at the G24 residue, which supports the hypothesis that hIAPP polymorphs form from a

SUBMITTER: Ostrander JS 

PROVIDER: S-EPMC6823637 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature