The Pro117 to glycine mutation of staphylococcal nuclease simplifies the unfolding—folding kinetics

FEBS Letters

Yamamoto, Kaori¹  Ishihara, Tsuyoshi¹  Kuwajima, Kunihiro¹  Sugai, Shintaro¹  Okayama, Naoki¹ 

[1] Department of Polymer Science, Faculty of Science, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060, Japan

关键词: Staphylococcal nuclease;    Folding mechanism;    Proline isomerization;    Stopped-flow technique;    Circular dichroism;    Site-directed mutagenesis;    SNase;    Staphylococcal nuclease;    CD;    circular dichroism;    pdTp;    thymidine 3′;    5′-diphosphate;    NMR;    nuclear magnetic resonance;    Nc and Nt;    two native species with the cis and trans forms;    respectively;    of the Lys116-Pro117 peptide bond;    P117G;    the Pro117 to glycine mutant;    IPTG;    isopropyl-β-D-thiogalactopyranoside;    EGTA;    [ethylenebis(oxyethylenenitrilo)]tetraacetic acid;   

DOI  :  10.1016/0014-5793(91)81243-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown