title: Engineering an improved crystal contact across a solvent-mediated interface of human fibroblast growth factor 1.
abstract: Large-volume protein crystals are a prerequisite for neutron diffraction studies and their production represents a bottleneck in obtaining neutron structures. Many protein crystals that permit the collection of high-resolution X-ray diffraction data are inappropriate for neutron diffraction owing to a plate-type morphology that limits the crystal volume. Human fibroblast growth factor 1 crystallizes in a plate morphology that yields atomic resolution X-ray diffraction data but has insufficient volume for neutron diffraction. The thin physical dimension has been identified as corresponding to the b cell edge and the X-ray structure identified a solvent-mediated crystal contact adjacent to position Glu81 that was hypothesized to limit efficient crystal growth in this dimension. In this report, a series of mutations at this crystal contact designed to both reduce side-chain entropy and replace the solvent-mediated interface with direct side-chain contacts are reported. The results suggest that improved crystal growth is achieved upon the introduction of direct crystal contacts, while little improvement is observed with side-chain entropy-reducing mutations alone.
authors.affiliation: Department of Biomedical Sciences, Florida State University, Tallahassee, 32306-4300, USA.
authors.forename: Akshaya K
authors.initials: AK
authors.lastname: Meher
authors.forename: Sachiko I
authors.initials: SI
authors.lastname: Blaber
authors.forename: Jihun
authors.initials: J
authors.lastname: Lee
authors.forename: Ejiro
authors.initials: E
authors.lastname: Honjo
authors.forename: Ryota
authors.initials: R
authors.lastname: Kuroki
authors.forename: Michael
authors.initials: M
authors.lastname: Blaber
mesh_terms: D003460:Crystallization / Q000379:methods*; D018360:Crystallography, X-Ray; D016220:Fibroblast Growth Factor 1 / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D033363:Neutron Diffraction; D011487:Protein Conformation; D015202:Protein Engineering / Q000379:methods*; D012997:Solvents / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D012997:Solvents; D016220:Fibroblast Growth Factor 1