title: Protein crystal nucleation in pores.
abstract: The most powerful method for protein structure determination is X-ray crystallography which relies on the availability of high quality crystals. Obtaining protein crystals is a major bottleneck, and inducing their nucleation is of crucial importance in this field. An effective method to form crystals is to introduce nucleation-inducing heterologous materials into the crystallization solution. Porous materials are exceptionally effective at inducing nucleation. It is shown here that a combined diffusion-adsorption effect can increase protein concentration inside pores, which enables crystal nucleation even under conditions where heterogeneous nucleation on flat surfaces is absent. Provided the pore is sufficiently narrow, protein molecules approach its walls and adsorb more frequently than they can escape. The decrease in the nucleation energy barrier is calculated, exhibiting its quantitative dependence on the confinement space and the energy of interaction with the pore walls. These results provide a detailed explanation of the effectiveness of porous materials for nucleation of protein crystals, and will be useful for optimal design of such materials.
authors.affiliation: Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. Bl. 11, 1113 Sofia, Bulgaria.
authors.forename: Christo N
authors.initials: CN
authors.lastname: Nanev
authors.affiliation: Structural and Supramolecular Chemistry Laboratory, Institute of Nanoscience and Nanotechnology, National Centre for Scientific Research "Demokritos", Athens 15310, Greece.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Saridakis
authors.affiliation: Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK.
authors.forename: Naomi E
authors.initials: NE
authors.lastname: Chayen
mesh_terms: D000327:Adsorption; D003460:Crystallization / Q000379:methods*; D018360:Crystallography, X-Ray; D004058:Diffusion; D004734:Energy Metabolism; D008962:Models, Theoretical; D016062:Porosity; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins