The role of non-specific interactions in a patchy model of protein crystallization
Journal of Chemical Physics
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Staneva, I., & Frenkel, D. (2015). The role of non-specific interactions in a patchy model of protein crystallization. Journal of Chemical Physics, 143 194511. https://doi.org/10.1063/1.4935369
We use a coarse-grained model for generic proteins to investigate the formation of structures with P2₁2₁2₁ symmetry, the most prevalent space group of protein crystals. To account for the string directionality of protein-protein interactions that has been suggested by previous studies, we represent proteins as spherical particles that are covered by a large number of small, attractive ‘patches’ that are randomly distributed on the protein surface. Attractive interactions between two proteins can then involve several pairs of patches interacting simultaneously. The results obtained with this model suggest that the factors influencing whether a unit cell will produce a crystal capable of growing are that particles attach to the previous layers with enough bonds and that the values of these interactions have a small spread, rather than merely being the unit cell with the lowest energy. We subsequently study the impact of interactions that are not part of crystalline contacts, and find that when these non-specific interactions are few and weaker than the crystal contacts, both nucleation and growth are successful. If the proportion of non-specific interactions is increased, crystal growth is still possible in a small range of model temperature.
This work was supported by EPSRC/NSF World Materials Network grant EP/J018619/1 and EPSRC Programme Grant EP/I001352/1.
External DOI: https://doi.org/10.1063/1.4935369
This record's URL: https://www.repository.cam.ac.uk/handle/1810/252407