Staphylokinase Displays Surprisingly Low Mechanical Stability

Single-molecule force spectroscopy (SMFS) and molecular dynamics (MD) simulations have revealed that shear topology is an important structural feature for mechanically stable proteins. Proteins containing a β-grasp fold display the typical shear topology and are generally of significant mechanical s...

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Publié dans:Langmuir : the ACS journal of surfaces and colloids. - 1985. - 33(2017), 4 vom: 31. Jan., Seite 1077-1083
Auteur principal: He, Chengzhi (Auteur)
Autres auteurs: Li, Hongbin
Format: Article en ligne
Langue:English
Publié: 2017
Accès à la collection:Langmuir : the ACS journal of surfaces and colloids
Sujets:Journal Article Research Support, Non-U.S. Gov't Solvents Metalloendopeptidases EC 3.4.24.- auR protein, Staphylococcus aureus EC 3.4.24.29
Description
Résumé:Single-molecule force spectroscopy (SMFS) and molecular dynamics (MD) simulations have revealed that shear topology is an important structural feature for mechanically stable proteins. Proteins containing a β-grasp fold display the typical shear topology and are generally of significant mechanical stability. In an effort to experimentally identify mechanically strong proteins using single-molecule atomic force microscopy, we found that staphylokinase (SAK), which has a typical β-grasp fold and was predicted to be mechanically stable in coarse-grained MD simulations, displays surprisingly low mechanical stability. At a pulling speed of 400 nm/s, SAK unfolds at ∼60 pN, making it the mechanically weakest protein among the β-grasp fold proteins that have been characterized experimentally. In contrast, its structural homologous protein streptokinase β domain displays significant mechanical stability under the same experimental condition. Our results showed that the large malleability of native-state SAK is largely responsible for its low mechanical stability. The molecular origin of this large malleability of SAK remains unknown. Our results reveal a hidden complexity in protein mechanics and call for a detailed investigation into the molecular determinants of the protein mechanical malleability
Description:Date Completed 10.09.2018
Date Revised 10.09.2018
published: Print-Electronic
Citation Status MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.6b04425