Single-molecule mechanical studies of chaperones and their clients

Single-molecule force spectroscopy provides access to the mechanics of biomolecules. Recently, magnetic and laser optical tweezers were applied in the studies of chaperones and their interaction with protein clients. Various aspects of the chaperone–client interactions can be revealed based on the mechanical probing strategies. First, when a chaperone is probed under load, one can examine the inner workings of the chaperone while it interacts with and works on the client protein. Second, when protein clients are probed under load, the action of chaperones on folding clients can be studied in great detail. Such client folding studies have given direct access to observing actions of chaperones in real-time, like foldase, unfoldase, and holdase activity. In this review, we introduce the various single molecule mechanical techniques and summarize recent single molecule mechanical studies on heat shock proteins, chaperone-mediated folding on the ribosome, SNARE folding, and studies of chaperones involved in the folding of membrane proteins. An outlook on significant future developments is given.
This work was supported by the German Research Foundation, Sonderforschungsbereich 1035, Projektnummer 201302640, Project A5 (to M.R.). G.Z. was supported by the Research Grant from the Grant Provided by Slovak Research and Development Agency (Grant No. APVV-18–0285), the Slovak Grant Agency VEGA No. 1/0024/22, KEGA No. 005UPJŠ-4/2021, and the Project BioPickmol, ITMS2014+: 313011AUW6 supported by the Operational Programme Integrated Infrastructure, funded by the ERDF.