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Supramolecular Approach to Electron Paramagnetic Resonance Distance Measurement of Spin-Labeled Proteins.
The Journal of Physical Chemistry B ( IF 2.8 ) Pub Date : 2020-04-13 , DOI: 10.1021/acs.jpcb.0c00743 Zhimin Yang 1 , Richard A Stein 2 , Thacien Ngendahimana 3 , Maren Pink 4 , Suchada Rajca 1 , Gunnar Jeschke 5 , Sandra S Eaton 3 , Gareth R Eaton 3 , Hassane S Mchaourab 2 , Andrzej Rajca 1
The Journal of Physical Chemistry B ( IF 2.8 ) Pub Date : 2020-04-13 , DOI: 10.1021/acs.jpcb.0c00743 Zhimin Yang 1 , Richard A Stein 2 , Thacien Ngendahimana 3 , Maren Pink 4 , Suchada Rajca 1 , Gunnar Jeschke 5 , Sandra S Eaton 3 , Gareth R Eaton 3 , Hassane S Mchaourab 2 , Andrzej Rajca 1
Affiliation
We demonstrate a host-guest molecular recognition approach to advance double electron-electron resonance (DEER) distance measurements of spin-labeled proteins. We synthesized an iodoacetamide derivative of 2,6-diazaadamantane nitroxide (DZD) spin label that could be doubly incorporated into T4 Lysozyme (T4L) by site-directed spin labeling with efficiency up to 50% per cysteine. The rigidity of the fused ring structure and absence of mobile methyl groups increase the spin echo dephasing time (Tm) at temperatures above 80 K. This enables DEER measurements of distances >4 nm in DZD-labeled T4L in glycerol/water at temperatures up to 150 K with increased sensitivity compared to that of a common spin label such as MTSL. Addition of β-cyclodextrin reduces the rotational correlation time of the label, slightly increases Tm, and most importantly, narrows (and slightly lengthens) the interspin distance distributions. The distance distributions are in good agreement with simulated distance distributions obtained by rotamer libraries. These results provide a foundation for developing supramolecular recognition to facilitate long-distance DEER measurements at near physiological temperatures.
中文翻译:
超分子方法测量自旋标记蛋白质的电子顺磁共振距离。
我们证明了来宾-客体分子识别方法来推进自旋标记蛋白质的双电子-电子共振(DEER)距离测量。我们合成了2,6-二氮杂金刚烷氮氧化物(DZD)自旋标记的碘乙酰胺衍生物,可通过定点自旋标记将其双重掺入T4溶菌酶(T4L)中,效率最高为每个半胱氨酸50%。在高于80 K的温度下,稠环结构的刚性和不存在可移动的甲基会增加自旋回波移相时间(Tm)。这使得能够在温度高达200°C的甘油/水中在DZD标记的T4L中进行DEER测量距离> 4 nm。与普通自旋标签(例如MTSL)相比,灵敏度提高到150K。添加β-环糊精可减少标记的旋转相关时间,略微增加Tm,最重要的是,缩小(并稍微延长)自旋间距离分布。距离分布与rotamer库获得的模拟距离分布非常吻合。这些结果为发展超分子识别提供了基础,以促进在近乎生理温度下的长距离DEER测量。
更新日期:2020-04-24
中文翻译:
超分子方法测量自旋标记蛋白质的电子顺磁共振距离。
我们证明了来宾-客体分子识别方法来推进自旋标记蛋白质的双电子-电子共振(DEER)距离测量。我们合成了2,6-二氮杂金刚烷氮氧化物(DZD)自旋标记的碘乙酰胺衍生物,可通过定点自旋标记将其双重掺入T4溶菌酶(T4L)中,效率最高为每个半胱氨酸50%。在高于80 K的温度下,稠环结构的刚性和不存在可移动的甲基会增加自旋回波移相时间(Tm)。这使得能够在温度高达200°C的甘油/水中在DZD标记的T4L中进行DEER测量距离> 4 nm。与普通自旋标签(例如MTSL)相比,灵敏度提高到150K。添加β-环糊精可减少标记的旋转相关时间,略微增加Tm,最重要的是,缩小(并稍微延长)自旋间距离分布。距离分布与rotamer库获得的模拟距离分布非常吻合。这些结果为发展超分子识别提供了基础,以促进在近乎生理温度下的长距离DEER测量。