Secrets of bond breaking
doi:10.1038/nindia.2010.149 Published online 26 October 2010
Researchers have developed an analytical theory that explains how weak bonds in biological proteins and cells break. Their theory is based on the Rouse model, which depicts a polymer coil as a series of beads and springs.
The research will have far-reaching implications as weak bonds are ubiquitous in biological structures. Weak bonds often function as adhesive contacts in an extended structure; for example, the internal bonds in a folded protein or a DNA/RNA loop.
In recent years, the breaking of weak bonds has received a lot of attention, mainly in the context of single-molecule experiments. Weak non-covalent bonds decide the stability of most macromolecular structures encountered in biological and other soft-matter systems.
To provide new insight into bond breakage, the researchers considered a stretched polymeric tether, fixed at one end and tethered to a weak bond at the other. They also used a fluid such as watery cytoplasm to investigate the effect of hydrodynamic interaction on the breakage rate.
The study showed that hydrodynamic interaction caused an increase in the breakage rate. This work implies that biological linkages (bonds), which are typically weak, are destabilized by hydrodynamic interaction. Bonds will break at a faster rate than if there is no watery medium present.
"This work will help us to understand in a quantitative way the effect of hydrodynamic interaction on the stability of biological structures," says lead researcher Anirban Sain.
- Das, S. G. et al. Effect of hydrodynamic interaction on polymeric tethers. Phys. Rev. E. 82, 041910 (2010) | Article