The Pro117 to glycine mutation of staphylococcal nuclease simplifies the unfolding-folding kinetics.
Kinetics of unfolding and refolding of a staphylococcal nuclease mutant, in which Pro117 is replaced by glycine, have been investigated by stopped-flow circular dichroism, and the results are compared with those for the wild-type protein. In contrast to the biphasic unfolding of the wild-type nuclease, the unfolding of the mutant is represented by a single-phase reaction, indicating that the biphasic unfolding for the wild-type protein is caused by cis-trans isomerization about the prolyl peptide bond in the native state. The proline mutation also simplifies the kinetic refolding. Importance of the results in elucidating the folding mechanism is discussed.
Department of Polymer Science, Faculty of Science, Hokkaido University, Japan.
K
K
Kuwajima
N
N
Okayama
K
K
Yamamoto
T
T
Ishihara
S
S
Sugai
D001426:Bacterial Proteins / Q000737:chemistry; D005998:Glycine / Q000737:chemistry; D007700:Kinetics; D008836:Micrococcal Nuclease / Q000737:chemistry*; D011392:Proline / Q000737:chemistry; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000737:chemistry; D013329:Structure-Activity Relationship
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D011392:Proline; D008836:Micrococcal Nuclease; D005998:Glycine