Properties and Crystal Structure of a -Barrel Folding Mutant

摘要: A mutant of a -barrel protein, rat intestinal fatty acid binding was predicted to be more stable than the wild-type protein due novel hydrogen bond. Equilibrium denaturation studies indicated opposite: V60N less stable. The folding transitions followed by CD and fluorescence were reversible two-state for both protein. However, rates renaturation faster. During unfolding, initial rate associated with 75- 80% all amplitude change. subsequent accounted remaining change proteins; thus intermediate state lacked secondary structure. folding, one detected after an burst phase mutant. An additional slower structure has been obtained is nearly identical prior crystal structures IFABP. Analysis mean differences in bond van der Waals interactions did not readily account stability loss mutation. significant average solvent accessible surface crystallographic displacement factors suggest entropic destabilization.