Thermodynamics of folding, stabilization, and binding in an engineered protein-protein complex
2004 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 126, no 36, 11220-11230 p.Article in journal (Refereed) Published
We analyzed the thermodynamics of a complex protein-protein binding interaction using the (engineered) Z(SPA-1) affibody and it's Z domain binding partner as a model. Free Z(SPA-1) exists in an equilibrium between a molten-globule-like (MG) state and a completely unfolded state, wheras a well-ordered structure is observed in the Z:Z(SPA-1) complex. The thermodynamics of the MG state unfolding equilibrium can be separated from the thermodynamics of binding and stabilization by combined analysis of isothermal titration calorimetry data and a separate van't Hoff analysis of thermal unfolding. We find that (i) the unfolding equilibrium of free Z(SPA-1) has only a small influence on effective binding affinity, that (ii) the Z:Z(SPA-1) interface is inconspicuous and structure-based energetics calculations suggest that it should be capable of supporting strong binding, but that (iii) the conformational stabilization of the MG state to a well-ordered structure in the Z:Z(SPA-1) complex is associated with a large change in conformational entropy that opposes binding.
Place, publisher, year, edition, pages
2004. Vol. 126, no 36, 11220-11230 p.
combinatorial libraries, staphylococcus-aureus, molten globules, affibody, domain, entropy, dna, microcalorimetry, recognition, parameters
Other Industrial Biotechnology
IdentifiersURN: urn:nbn:se:kth:diva-6406DOI: 10.1021/ja047727yISI: 000223799900035ScopusID: 2-s2.0-4544277195OAI: oai:DiVA.org:kth-6406DiVA: diva2:11107
QC 20101025 QC 201109162006-11-222006-11-222011-09-16Bibliographically approved