Joint Mechanical Engineering and Biomedical Engineering Seminar: Dr. Matthew Lang

Misfolding, Folding and Unfolding

Associate Professor, Biological Engineering and Mechanical Engineering, Massachusetts Institute of Technology

Abstract

Single molecule methods applied to molecular and cellular systems will be introduced. The first part of the talk will focus on misfolding in amyloid fibers including force fluorescence microscopy to measure their properties. Detailed studies of two molecular motors will follow: kinesin which transports cargo and ClpXP which recognizes proteins, mechanically unfolds, transports and degrades them. Force generation in the kinesin motor protein is driven by folding between the N-terminal cover strand and neck linker to form the cover neck bundle, a mechanism that is directly tested by optical trapping measurements of engineered kinesin motor mutants. The ClpXP protease, a member of the AAA+ class of motors, destroys protein substrates by unfolding them and coordinating machinery for recognition, denaturation, translocation and degradation, events which are measured a new single-molecule fluorescence assay using a series of fluorescently labeled GFP based substrates.