Application of site-specific 19F paramagnetic relaxation enhancement to distinguish two different conformations of a multidomain protein

作者：Shi P.; Li D.; Li J.; Chen H.; Wu F.; Xiong Y.; Tian C.

来源：Journal of Physical Chemistry Letters, 2012, 3(1): 34-37.

Paramagnetic relaxation enhancement (PRE) provides long-distance restraints in solution NMR protein structural studies. It has been shown previously that L27tan, a protein with tandem L27-domains, has two possible conformations. Here, 19F was site-specifically introduced to L27tan via the incorporation of an unnatural amino acid, trifluoromethyl-phenylalanine (tfmF). Different 19F signal intensity attenuations were observed at different L27tan sites, due to different distances between the site-specifically incorporated tfmF and site-directed spin radical labeling. Analysis of the 19F detection PRE showed that the L27tan protein had a closed conformation in solution. This 19F detection PRE method could be further applied in distance measurements for proteins of large size, including multidomain proteins or membrane proteins.

• 出版日期2012
• 单位中国科学技术大学