Nanometer-Range Distance Measurement in a Protein Using Mn2+ Tags

详细信息    查看全文

• 作者：Debamalya Banerjee ; Hiromasa Yagi ; Thomas Huber ; Gottfried Otting ; Daniella Goldfarb
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2012
• 出版时间：January 19, 2012
• 年：2012
• 卷：3
• 期：2
• 页码：157-160
• 全文大小：288K
• 年卷期：v.3,no.2(January 19, 2012)
• ISSN：1948-7185

文摘

Pulse electron paramagnetic resonance measurements of long-range (nm scale) distances between spin labels site-specifically attached to biomacromolecules have proven highly effective in structural studies. The most commonly used spin labels are stable nitroxide radicals, and measurements are usually carried out at X-band frequencies (9.5 GHz, 0.35 T). Higher magnetic fields open new possibilities for distance measurements with increased sensitivity using alternative spin labels containing half-integer high-spin metal ions. Here we demonstrate W-band (95 GHz) pulse double electron鈥揺lectron resonance (DEER) distance measurements in a protein labeled with two Mn²⁺-EDTA tags. The distance distribution obtained is in excellent agreement with model calculations based on the known solution NMR structure. Thus, site-specific labeling with Mn²⁺ tags opens a highly promising approach to nanometer distance measurements in biological macromolecules.

Keywords:

EPR; DEER; PELDOR; high field; spin labeling; distance measurements; Mn²⁺-EDTA