Dysfunction in biological systems usually begins at the molecular level. Small perturbations can produce highly consequential effects on the overall system: oxidative modifications, for example, or point mutations that alter function in just a few proteins. To understand such phenomena, it is necessary to characterize not only the underlying perturbations and their effect on biomolecular function, but to also investigate implications for the entire system. The Biostructure and Function group approaches biological problems from both directions. We use biochemistry, biophysics, and structural biology to understand the function of key system components. Simultaneously, we use mass spectrometry-based proteomics and metabolomics to achieve a systems-level understanding that ties back to root causes at the molecular level. (See examples here and here.)​