The study of proteins with the same architecture, but different sequence has proven to be a valuable tool in the protein folding field. As a prelude to studies on the folding mechanism of spectrin domains we present the kinetic characterisation of the wild-type forms of the 15th, 16th, and 17th domains of chicken brain alpha-spectrin (referred to as R15, R16 and R17, respectively). We show that the proteins all behave in a two-state manner, with different kinetic properties. The folding rate varies remarkably between different members, with a 5000-fold variation in folding rate and 3000-fold variation in unfolding rate seen for proteins differing only 1 kcal mol(-1) in stability. We show clear evidence for significant complexity in the energy landscape of R16, which shows a change in amplitude outside the stopped-flow timescale and curvature in the unfolding arm of the chevron plot. The accompanying paper describes the characterisation of the folding pathway of this domain. Study holds ProTherm entries: 18102, 18103, 18104, 18105, 18106 Extra Details: 15th domain protein folding; helix-bundle; spectrin; residual structure; homologue
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:50 p.m.
|Number of data points||12|
|Proteins||Spectrin alpha chain, non-erythrocytic 1 ; Spectrin alpha chain, non-erythrocytic 1|
|Assays/Quantities/Protocols||Experimental Assay: m ; Experimental Assay: dG_H2O ; Derived Quantity: ddG_H2O|
|Libraries||Mutations for sequence AKLNESHRLHQFFRDMDDEESWIKEKKLLVSSEDYGRDLTGVQNLRKKHKRLEAELAAHEPAIQGVLDTGKKLSDDNTIGKEEIQQRLAQFVDHWKELKQLAAARGQRLE|