Open AccessMutagenesis of the crystal contact of acidic fibroblast growth factor
Author(s) -
Honjo Eijiro,
Tamada Taro,
Adachi Motoyasu,
Kuroki Ryota,
Meher Akshaya,
Blaber Michael
Publication year - 2008
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049508004470
Subject(s) - crystallography , crystal (programming language) , crystal structure , sodium formate , protein crystallization , mutant , crystal growth , hydrogen bond , formate , chemistry , crystal habit , materials science , molecule , crystallization , biochemistry , inorganic chemistry , organic chemistry , computer science , gene , programming language , catalysis
An attempt has been made to improve a crystal contact of human acidic fibroblast growth factor (haFGF; 140 amino acids) to control the crystal growth, because haFGF crystallizes only as a thin‐plate form, yielding crystals suitable for X‐ray but not neutron diffraction. X‐ray crystal analysis of haFGF showed that the Glu81 side chain, located at a crystal contact between haFGF molecules, is in close proximity with an identical residue related by crystallographic symmetry, suggesting that charge repulsion may disrupt suitable crystal‐packing interactions. To investigate whether the Glu residue affects the crystal‐packing interactions, haFGF mutants in which Glu81 was replaced by Ala, Val, Leu, Ser and Thr were constructed. Although crystals of the Ala and Leu mutants were grown as a thin‐plate form by the same precipitant (formate) as the wild type, crystals of the Ser and Thr mutants were grown with increased thickness, yielding a larger overall crystal volume. X‐ray structural analysis of the Ser mutant determined at 1.35 Å resolution revealed that the hydroxy groups of Ser are linked by hydrogen bonds mediated by the formate used as a precipitant. This approach to engineering crystal contacts may contribute to the development of large protein crystals for neutron crystallography.