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Biology subjects

Peters, J. S.

Publications and source records attributed to Peters, J. S..

3 recordsLinked to original sources

Continuous mass photometry by single molecule trapping

The dynamic choreography of biomolecular interactions underpins the processes of life, but its direct observation remains challenging. Here, we introduce confined diffusion mass photometry, enabling hour-long, mass-resolved observation of individual biomolecules, their complexes and interactions with up to sub-kDa mass precision and ms temporal resolution. Our approach represents a quantitative time-resolved single-molecule measurement modality for studying complex biomolecular mechanisms in action.

biophysics↗

Deep learning-based event classification of mass photometry data for optimal mass measurement at the single-molecule level

Mass photometry (MP) is a powerful technique for studying biomolecular structure, interactions, and dynamics in solution. It detects and quantifies small reflectivity changes at a glass-water interface during protein (un)binding, with signals typically averaged over 100 milliseconds. However, particle motion at the point of single-molecule measurement can compromise key metrics such as mass resolution, sensitivity, and concentration. We present a three-dimensional convolutional residual network trained via supervised learning to classify landing events based on their spatiotemporal dynamics. By analysing 3D event thumbnails, our method isolates optimal single-molecule measurements, eliminating cumulative histogram artifacts and improving resolving power by up to a factor of 2. Validated across diverse experimental datasets--including resolved and partially resolved samples, and varying masses, concentrations, and integration times--our approach delivers robust performance under (sub)optimal conditions. Our approach provides measurement-level data-driven feedback, facilitating high quality MP measurements in challenging scenarios.

biophysics↗

A quantitative description for optical mass measurement of single biomolecules

Label-free detection of single biomolecules in solution has been achieved using a variety of experimental approaches over the past decade. Yet, our understanding of the magnitude of the optical contrast and its relationship to the underlying atomic structure, as well as the achievable measurement sensitivity and precision remain poorly defined. Here, we use a Fourier optics approach combined with an atomic structure-based molecular polarizability model to simulate mass photometry experiments from first principles. We find excellent agreement between several key experimentally-determined parameters such as optical contrast-to-mass conversion, achievable mass accuracy and molecular shape/orientation dependence. This allows us to determine detection sensitivity and measurement precision that is mostly independent of the optical detection approach chosen, resulting in a general framework for light-based single molecule detection and quantification.

biophysics↗