Conformation switching of single native proteins revealed by nanomechanical probing without a pulling force

Abstract

Protein conformational changes are essential to biological function, and the heterogeneous nature of the corresponding protein states provokes an interest to measure conformational changes at the single molecule level.

Applications of magnetic and electromagnetic forces in micro-analytical systems

“…They demonstrated a limit of detection lower than 5 pM for biotinylated BSA in human plasma in an assay time of less than 3 min. This method was applied for the analysis of prostate-specific antigen (PSA), 208 the detection of conformation switching of single native proteins, 209 and fundamental research of the kinetic mechanisms of aggregation 210 and inter-particle biomolecular reactivity. 211 The response of MNPs to an alternating magnetic field ranging from kHz to MHz has been used for recent biomedical applications and nanoscale measurement techniques, such as magnetic particle imaging (MPI), 212,213 magnetic hyperthermia therapy (MHT), 214,215 magnetic particle nanorheology (MPN), [216][217][218] and homogeneous biosensing method.…”

“…They demonstrated a limit of detection lower than 5 pM for biotinylated BSA in human plasma in an assay time of less than 3 min. This method was applied for the analysis of prostate-specific antigen (PSA), 208 the detection of conformation switching of single native proteins, 209 and fundamental research of the kinetic mechanisms of aggregation 210 and inter-particle biomolecular reactivity. 211…”

Single-molecule calorimeter and free energy landscape

“…The thermal force of a biomolecular system alters the shaken motion of molecules, which can be optically probed by a linked nanoparticle (26)(27)(28). Tethered nanoparticle motion describes the conformational changes of linked soft molecule and dynamic interactions, which is achieved by tracking the motion behavior of a nanoparticle probe tethered to a substrate with a single biomolecule.…”

Imaging the Heterogeneous Localization of a Single Molecule

“…9 However, an average of 100 single-molecule trajectories is performed to overcome the limitations of the optical stability (e.g., quenching or blinking process) and fluorescence strength of the target fluorophore molecules. 15 An optical microscope based on single-nanoparticle mobility has been developed to study the biological processes such as enzymatic activity and transcription of single RNA polymerase molecules. 16,17 The binding activity of lipid membraneassociated molecules is determined by tracking the diffusion of membrane-tethered gold nanoparticles (AuNPs).…”

“…These technologies have provided a platform to resolve the spatial information of single molecules, which are important to study the molecular structure, function, binding interactions, and cellular processes at a high level of spatial resolution . However, an average of 100 single-molecule trajectories is performed to overcome the limitations of the optical stability (e.g., quenching or blinking process) and fluorescence strength of the target fluorophore molecules …”