title: Probing Small Molecule Binding to Unfolded Polyprotein Based on its Elasticity and Refolding.
abstract: Unfolded protein, a disordered structure found before folding of newly synthesized protein or after protein denaturation, is a substrate for binding by many cellular factors such as heat-stable proteins, chaperones, and many small molecules. However, it is challenging to directly probe such interactions in physiological solution conditions because proteins are largely in their folded state. In this work we probed small molecule binding to mechanically unfolded polyprotein using sodium dodecyl sulfate (SDS) as an example. The effect of binding is quantified based on changes in the elasticity and refolding of the unfolded polyprotein in the presence of SDS. We show that this single-molecule mechanical detection of binding to unfolded polyprotein can serve, to our knowledge, as a novel label-free assay with a great potential to study many factors that interact with unfolded protein domains, which underlie many important biological processes.
authors.affiliation: Department of Physics, National University of Singapore, Singapore, Singapore; Mechanobiology Institute, National University of Singapore, Singapore, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore, Singapore.
authors.forename: Ricksen S
authors.initials: RS
authors.lastname: Winardhi
authors.affiliation: Department of Physics, National University of Singapore, Singapore, Singapore; Mechanobiology Institute, National University of Singapore, Singapore, Singapore.
authors.forename: Qingnan
authors.initials: Q
authors.lastname: Tang
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore, Singapore.
authors.forename: Jin
authors.initials: J
authors.lastname: Chen
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore, Singapore.
authors.forename: Mingxi
authors.initials: M
authors.lastname: Yao
authors.affiliation: Department of Physics, National University of Singapore, Singapore, Singapore; Mechanobiology Institute, National University of Singapore, Singapore, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore, Singapore. Electronic address: phyyj@nus.edu.sg.
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
mesh_terms: D004548:Elasticity; D019791:Guanidine / Q000378:metabolism / Q000494:pharmacology; D008958:Models, Molecular; D011489:Protein Denaturation / Q000187:drug effects; D058849:Protein Refolding / Q000187:drug effects; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate / Q000378:metabolism / Q000494:pharmacology; D014508:Urea / Q000378:metabolism / Q000494:pharmacology
chemical_list: D011506:Proteins; D012967:Sodium Dodecyl Sulfate; D014508:Urea; D019791:Guanidine