Attachment of an NMR-invisible solubility enhancement tag using a sortase-mediated protein ligation method
Sample solubility is essential for structural studies of proteins by solution NMR. Attachment of a solubility enhancement tag, such as GB1, MBP and thioredoxin, to a target protein has been used for this purpose. However, signal overlap of the tag with the target protein often made the spectral analysis difficult. Here we report a sortase-mediated protein ligation method to eliminate NMR signals arising from the tag by preparing the isotopically labeled target protein attached with the non-labeled GB1 tag at the C-terminus.
KeywordsSortase Protein ligation GB1 Intein INSET Solubility enhancement
Sodium dodecyl sulfate-polyacrylamide gel electrophoresis
Isotopically invisible solubility/stability enhancement tag
This work was supported by Grants-in-Aid for Scientific Research and the National Project on “Targeted Proteins Research Program” from the Ministry of Education, Science and Culture of Japan.