Biological systems respond to environmental and chemical perturbations with sophisticated processes that often involve conformational motions of their protein building blocks. These motions have been difficult to resolve due to limitations in sensitivity, specificity, and time resolution. We overcome these limitations with single-molecule methods, including advances in data analysis that resolve multiple microsecond dynamics occurring in parallel within individual proteins. We explore two processes: (1) photoprotective quenching in oxygenic photosynthesis, uncovering two parallel processes that respond to slow and fast changes in sunlight; and (2) the molecular-level motions of a cancer drug target, identifying a previously hidden connection between the extracellular and intracellular domains via a single transmembrane alpha-helix.

[held as part of colloquium]