NMR IDENTIFICATION OF PROTEIN SURFACES USING PARAMAGNETIC PROBES
NMR IDENTIFICATION OF PROTEIN SURFACES USING PARAMAGNETIC PROBES
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DOI：
10.1021/bi00495a005
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发表时间：
1990-10-30
期刊：
影响因子：
2.9
通讯作者：
KOPPLE, KD
中科院分区：
文献类型：
--
作者：
PETROS, AM;MUELLER, L;KOPPLE, KD
顺磁性物质使二维相关核磁共振谱线变宽，从而抵消反相交叉峰分量。检查这种效应的特异性以确定其用于鉴定蛋白质表面残基的效用。泛素和鸡蛋白色溶菌酶，其中的X射线晶体结构和质子NMR分配是可用的，作为测试用例。采用两种弛豫试剂，4-羟基-2，2，6-四甲基哌啶基-1-氧基和钆（III）二亚乙基三胺五乙酸络合物离子。在双量子折叠质子相关（DQF-COSY）光谱中试剂产生的侧链交叉峰体积减少与相应残基的溶剂暴露侧链表面积之间寻求相关性。镧系元素复合物产生强烈的影响归因于与羧酸基团的关联，但在描绘表面残基，否则是没有用的。硝酰基，另一方面，产生了明确的区别之间的瓦尔，亮氨酸，和Ile残基，通常在晶体中的侧链暴露，虽然一致的相关性没有观察到与其他类型的残基。虽然注意到可能的特定蛋白质-硝酰基缔合的实例，但硝酰基似乎是用于鉴定疏水表面残基的工具。
Paramagnetic agents produce line broadening and thus cancellation of anti phase cross-peak components in two-dimensional correlated nuclear magnetic resonance spectra. The specificity of this effect was examined to determine its utility for identifying surface residues of proteins. Ubiquitin and hen egg white lysozyme, for which X-ray crystal structures and proton NMR assignments are available, served as test cases. Two relaxation reagents were employed, 4-hydroxy-2,2,6,-tetramethylpiperidinyl-1-oxy and the gadolinium(III) diethylenetriaminepentaacetate complex ion. Correlations were sought between reagent-produced decreases of side-chain cross-peak volumes in double-quantum-foltered proton correlation (DQF-COSY) spectra and the solvent-exposed side-chain surface area of the corresponding residues. The lanthanide complex produced strong effects ascribable to association with carboxylate groups but was not otherwise useful in delineating surface residues. The nitroxyl, on the other hand, produced clear distinctions among the Val, Leu, and Ile residues that generally paralleled side-chain exposure in the crystal, although consistent correlations were not observed with residues of other types. Although an instance of possible specific protein-nitroxyl association was noted, the nitroxyl appears to be a tool for identifying hydrophobic surface residues.