Application of Site-Specific 19F Paramagnetic Relaxation Enhancement to Distinguish two Different Conformations of a Multidomain Protein

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• 作者：Pan Shi ; Dong Li ; Juan Li ; Hongwei Chen ; Fangming Wu ; Ying Xiong ; Changlin Tian
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2012
• 出版时间：January 5, 2012
• 年：2012
• 卷：3
• 期：1
• 页码：34-37
• 全文大小：245K
• 年卷期：v.3,no.1(January 5, 2012)
• ISSN：1948-7185

文摘

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.

Keywords:

¹⁹F detection; site-specific labeling; paramagnetic relaxation enhancement; distance measurement; multidomain protein