Mechanical Processes in Biochemistry

Abstract

Mechanical processes are involved in nearly every facet of the cell cycle. Mechanical forces are generated in the cell during processes as diverse as chromosomal segregation, replication, transcription, translation, translocation of proteins across membranes, cell locomotion, and catalyzed protein and nucleic acid folding and unfolding, among others. Because force is a product of all these reactions, biochemists are beginning to directly apply external forces to these processes to alter the extent or even the fate of these reactions hoping to reveal their underlying molecular mechanisms. This review provides the conceptual framework to understand the role of mechanical force in biochemistry.

Protein-DNA chimeras for single molecule mechanical folding studies with the optical tweezers

“…Proteins are subject to mechanical stress in a variety of biological processes (Bustamante et al 2004) and the response of proteins to mechanical stimuli is largely dependent on their particular mechanical properties and varies among different systems. Extracellular matrix proteins, for example, such as fibronectin and tenascin, as well as intracellular cytoskeletal proteins, such as spectrin and α-actinin, resist mechanical stress to help retain the shape of tissues and cells.…”

Assay to mechanically tune and optically probe fibrillar fibronectin conformations from fully relaxed to breakage

“…Yet, the underlying molecular mechanisms by which physical factors, including force and the mechanical properties of matrices, are converted into biochemical signals that ultimately regulate protein expression are only beginning to be explored (Kostic and Sheetz, 2006). One focus is to identify proteins whose structure/function relationship can be altered by mechanical forces, causing for example the opening of ion channels, a change in the spatial presentation of binding sites, or the exposure of otherwise cryptic binding sites (for reviews see Bustamante et al, 2004;Kung, 2005;Vogel, 2006;Vogel and Sheetz, 2006;Arcangeli and Becchetti, 2006).…”

Honey, I shrunk the DNA: DNA length as a probe for nucleic‐acid enzyme activity

“…The large range in forces that can be applied (100 fN-100 pN) makes optical trapping techniques suitable for the investigation of the effect of force on biochemical processes. 49 The high spatial accuracy associated with optical trapping has enabled measurements of translocating nucleicacid enzymes with a resolution of a single base pair. 19 Generally, only a small number of beads can be trapped simultaneously, making multiplexed observations difficult.…”