Crystallization and preliminary crystallographic analyses of human insulin mutant B9(Ser→Asp) in different aggregation forms

B9(Ser→Asp) insulin, one of the fast-acting insulin mutants produced by protein engineering, has been crystallized. Three crystal forms have been obtained, which belong to orthorhombic, tetragonal and rhombohedral system, respectively. Each crystal form contains different aggregation units of the mutant, i.e. dimer or hexamer. The diffraction data of the former two have been collected beyond 0.2 nm resolution. The structural analyses and comparisons will provide some information about insulin ’ s self-association and the structural basis of the fast absorption produced from the mutation.