Folding pathway of guanidine-denatured disulfide-intact wild-type and mutant bovine pancreatic ribonuclease A.
The refolding kinetics of guanidine-denatured disulfide-intact bovine pancreatic ribonuclease A (RNase A) and its proline-42-to-alanine mutant (Pro42Ala) have been studied by monitoring tyrosine burial and 2'-cytidine monophosphate (2'CMP) inhibitor binding. The folding rate for wild-type RNase A is faster in the presence of the inhibitor 2'CMP than in its absence, indicating that the transition-state structure in the rate-determining step is stabilized by 2'CMP. The folding rate monitored by 2'CMP binding to the major slow-folding species of Pro42Ala RNase A is faster than the folding rate monitored by tyrosine burial; however, the folding rate monitored by inhibitor binding to the minor slow-folding species is decreased significantly over the folding rate monitored by tyrosine burial, indicating that the major and minor slow-folding species of Pro42Ala fold to the native state with different transition-state conformations in the rate-determining step.
T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23
CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL GENE-N GENE-N GENE-Y GENE-N GENE-Y GENE-Y GENE-N GENE-Y GENE-Y
proline alanine tyrosine 2'-cytidine monophosphate 2'CMP guanidine 2'CMP 2'CMP disulfide 2'CMP tyrosine tyrosine guanidine disulfide proline-42-to-alanine Pro42Ala RNase A Pro42Ala RNase A bovine pancreatic ribonuclease A Pro42Ala RNase A bovine pancreatic ribonuclease A