Supplementary Figure 11: The position of the PEG-polypeptide linker bound to the tip affects the distance of the force peak stretching the linker.
From: Imaging G protein–coupled receptors while quantifying their ligand-binding free-energy landscape
The stretching of the PEG-polypeptide linker under force is described combining the model describing the PEG elasticity and the WLC model describing the polypeptide elasticity (see Supplementary Note). Independent of the position at which the PEG-polypeptide linker is chemically anchored to the AFM tip the force-distance characteristics describing the stretching of the linker is always similar since in all cases the linker is bound via one terminal end to the AFM tip and with the other terminal end adheres to the receptor. However, due to the vertical position at which the linker is anchored to the tip, the first part of the force-distance characteristics describing the stretching of the PEG-polypeptide linker can be hidden by relative distance "∆d" value (dashed line).
