Stability and orientation of cecropin P1 on maleimide self-assembled monolayer (SAM) surfaces and suggested functional mutations

One of the main challenges of biosensor design is to understand the protein or peptide stability on the chip in high resolution structural detail. Since conventional experimental methods are limited by the resolution for their applications on surface tethered peptides/proteins, a recently developed coarse grained simulation method is employed to explore the peptide/surface interaction in residue-level resolution. This work shows how the coarse grained model successfully describes peptide–surface interactions by evaluating thermal stability of the peptide cecropin P1 in bulk solution and on surfaces by physical adsorption and chemical tethering. The simulation also reproduces observations of peptide orientations on the self-assembled monolayer surface from earlier experimental work. Additionally, using knowledge obtained from the simulations, specific mutations are suggested and the desired structure and pose on the surface is obtained. In summary, this work sheds a light on the reasonable biosensor design that is guided by simulations.

Graphical abstractThis work shows a successful case of simulation-guided redesigning of an antimicrobial peptide, which leads a change of peptide orientation on a maleimide SAM surface with its N-terminus tethered. Furthermore, the thermal stability of the wild-type cecropin P1 is discussed for peptides chemically tethered, physicosorbed on the surface, and in the bulk solution, which is consistent with experimental observations.Figure optionsDownload full-size imageDownload as PowerPoint slide