Force and function: probing proteins with AFM-based force spectroscopy.

Forces play a pivotal role in life, and the response of live systems to forces requires molecules and molecular interactions with adequate properties to counteract both in a passive and also, if needed, in an active, dynamic manner. However, at the level of individual molecules these forces are so minute, that the development of sophisticated experiments to measure and control them was required. With the maturation of these techniques, particularly the AFM-based single-molecule force spectroscopy into commercial instruments, the scope has widened considerably and more and more studies shed light onto the different aspects of biomolecular mechanics. Many surprises turned up and more are waiting for us.