Quantifying the heterogeneity of macromolecular machines by mass photometry.

ABSTRACT: Sample purity is central to in vitro studies of protein function and regulation, and to the efficiency and success of structural studies using techniques such as x-ray crystallography and cryo-electron microscopy (cryo-EM). Here, we show that mass photometry (MP) can accurately characterize the heterogeneity of a sample using minimal material with high resolution within a matter of minutes. To benchmark our approach, we use negative stain electron microscopy (nsEM), a popular method for EM sample screening. We include typical workflows developed for structure determination that involve multi-step purification of a multi-subunit ubiquitin ligase and chemical cross-linking steps. When assessing the integrity and stability of large molecular complexes such as the proteasome, we detect and qua

SUBMITTER: Sonn-Segev A 

PROVIDER: S-EPMC7156492 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature