Structural analysis of the stable form of fibroblast growth factor 2 – FGF2-STAB

• Published in: Journal of structural biology. X Vol. 10; p. 100112
• Main Authors: de La Bourdonnaye, Gabin, Marek, Martin, Ghazalova, Tereza, Damborsky, Jiri, Pachl, Petr, Brynda, Jiri, Stepankova, Veronika, Chaloupkova, Radka
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2024; Elsevier
• Subjects: Protein flexibility; Stabilized fibroblast growth factor 2; X-ray structural analysis; X-ray structural analysis; Protein flexibility; Stabilized fibroblast growth factor 2
• DOI: 10.1016/j.yjsbx.2024.100112
• ISSN: 2590-1524

[Display omitted] •Structural analysis of FGF2-STAB performed to get molecular inside into its unique properties.•Crystal structure of FGF2-STAB solved at 1.31 Å resolution, high similarity with FGF2-wt structure identified.•Protein stability explained by newly formed hydrophobic interactions, polar contacts, and one hydrogen bond.•Improved biological activity of FGF2-STAB linked with identified higher flexibility of the receptor binding region.•Higher flexibility of the receptor binding region likely caused by S109E substitution. Fibroblast growth factor 2 (FGF2) is a signaling protein that plays a significant role in tissue development and repair. FGF2 binds to fibroblast growth factor receptors (FGFRs) alongside its co-factor heparin, which protects FGF2 from degradation. The binding between FGF2 and FGFRs induces intracellular signaling pathways such as RAS-MAPK, PI3K-AKT, and STAT. FGF2 has strong potential for application in cell culturing, wound healing, and cosmetics but the potential is severely limited by its low protein stability. The thermostable variant FGF2-STAB was constructed by computer-assisted protein engineering to overcome the natural limitation of FGF2. Previously reported characterization of FGF2-STAB revealed an enhanced ability to induce MAP/ERK signaling while having a lower dependence on heparin when compared with FGF2-wt. Here we report the crystal structure of FGF2-STAB solved at 1.3 Å resolution. Protein stabilization is achieved by newly formed hydrophobic interactions, polar contacts, and one additional hydrogen bond. The overall structure of FGF2-STAB is similar to FGF2-wt and does not reveal information on the experimentally observed lower dependence on heparin. A noticeable difference in flexibility in the receptor binding region can explain the differences in signaling between FGF2-STAB and its wild-type counterpart. Our structural analysis provided molecular insights into the stabilization and unique biological properties of FGF2-STAB.