2CK2

Structure of core-swapped mutant of fibronectin

Summary for 2CK2

• Entry DOI: 10.2210/pdb2ck2/pdb
• Related: 1E88 1E8B 1FBR 1FNA 1FNF 1FNH 1J8K 1O9A 1OWW 1Q38 1QGB 1QO6 1TTF 1TTG 2CG6 2CG7 2FN2 2FNB
• Descriptor: HUMAN FIBRONECTIN, ACETYL GROUP (3 entities in total)
• Functional Keywords: sulfation, acute phase, glycoprotein, cell adhesion, pyrrolidone carboxylic acid, heparin-binding, phosphorylation, alternative splicing, signaling protein
• Biological source: HOMO SAPIENS (HUMAN)
• Cellular location: Secreted, extracellular space, extracellular matrix: P02751
• Total number of polymer chains: 2
• Total formula weight: 20430.74

Authors

Ng, S.P.,Billings, K.S.,Ohashi, T.,Allen, M.D.,Best, R.B.,Randles, L.G.,Erickson, H.P.,Clarke, J. (deposition date: 2006-04-10, release date: 2007-04-10, Last modification date: 2023-12-13)

Primary citation

Ng, S.P.,Billings, K.S.,Ohashi, T.,Allen, M.D.,Best, R.B.,Randles, L.G.,Erickson, H.P.,Clarke, J.
Designing an Extracellular Matrix Protein with Enhanced Mechanical Stability
Proc.Natl.Acad.Sci.USA, 104:9633-, 2007

PubMed Abstract: The extracellular matrix proteins tenascin and fibronectin experience significant mechanical forces in vivo. Both contain a number of tandem repeating homologous fibronectin type III (fnIII) domains, and atomic force microscopy experiments have demonstrated that the mechanical strength of these domains can vary significantly. Previous work has shown that mutations in the core of an fnIII domain from human tenascin (TNfn3) reduce the unfolding force of that domain significantly: The composition of the core is apparently crucial to the mechanical stability of these proteins. Based on these results, we have used rational redesign to increase the mechanical stability of the 10th fnIII domain of human fibronectin, FNfn10, which is directly involved in integrin binding. The hydrophobic core of FNfn10 was replaced with that of the homologous, mechanically stronger TNfn3 domain. Despite the extensive substitution, FNoTNc retains both the three-dimensional structure and the cell adhesion activity of FNfn10. Atomic force microscopy experiments reveal that the unfolding forces of the engineered protein FNoTNc increase by approximately 20% to match those of TNfn3. Thus, we have specifically designed a protein with increased mechanical stability. Our results demonstrate that core engineering can be used to change the mechanical strength of proteins while retaining functional surface interactions.

PubMed: 17535921
DOI: 10.1073/PNAS.0609901104

Experimental method

X-RAY DIFFRACTION (2 Å)