4Q91

Crystal structure of C16A/K12V/C117V/P134V mutant of human acidic fibroblast growth factor

Summary for 4Q91

• Entry DOI: 10.2210/pdb4q91/pdb
• Related: 1JQZ 1JY0 1RG8 2AFG 3FJE 3FJF 3FJH 3FJK 4Q9G 4Q9P 4QAL
• Descriptor: Fibroblast growth factor 1, FORMIC ACID, PHOSPHATE ION, ... (4 entities in total)
• Functional Keywords: beta-trefoil, growth factor, fgfr binding, heparin binding, extracellular matrix, protein binding
• Biological source: Homo sapiens (human)
• Cellular location: Secreted: P05230
• Total number of polymer chains: 2
• Total formula weight: 33570.37

Authors

Xia, X.,Blaber, M. (deposition date: 2014-04-28, release date: 2015-03-11, Last modification date: 2024-02-28)

Primary citation

Xia, X.,Longo, L.M.,Blaber, M.
Mutation choice to eliminate buried free cysteines in protein therapeutics.
J.Pharm.Sci., 104:566-576, 2015

PubMed Abstract: Buried free-cysteine (Cys) residues can contribute to an irreversible unfolding pathway that promotes protein aggregation, increases immunogenic potential, and significantly reduces protein functional half-life. Consequently, mutation of buried free-Cys residues can result in significant improvement in the storage, reconstitution, and pharmacokinetic properties of protein-based therapeutics. Mutational design to eliminate buried free-Cys residues typically follows one of two common heuristics: either substitution by Ser (polar and isosteric), or substitution by Ala or Val (hydrophobic); however, a detailed structural and thermodynamic understanding of Cys mutations is lacking. We report a comprehensive structure and stability study of Ala, Ser, Thr, and Val mutations at each of the three buried free-Cys positions (Cys16, Cys83, and Cys117) in fibroblast growth factor-1. Mutation was almost universally destabilizing, indicating a general optimization for the wild-type Cys, including van der Waals and H-bond interactions. Structural response to Cys mutation characteristically involved changes to maintain, or effectively substitute, local H-bond interactions-by either structural collapse to accommodate the smaller oxygen radius of Ser/Thr, or conversely, expansion to enable inclusion of novel H-bonding solvent. Despite the diverse structural effects, the least destabilizing average substitution at each position was Ala, and not isosteric Ser.

PubMed: 25312595
DOI: 10.1002/jps.24188

Experimental method

X-RAY DIFFRACTION (1.799 Å)