Figure 1

Unfolding of a membrane protein: a single molecule is attached between the tip of a cantilever and the sample, while a force is applied to unfold and stretch the protein. The resulting Force-Distance (F-D) curve indicates protein unfolding. The force peaks are fitted by the Worm-Like Chain (WLC) model and are correlated with unfolding of the protein's secondary structure elements (amino acids). The force peaks are related to energy barriers, i.e., energetically favored regions of the protein structure [13].