Deuterium exchange and mass spectrometry reveal the interaction differences of two synthetic modulators of RXRalpha LBD.
Deuterium exchange and mass spectrometry reveal the interaction differences of two synthetic modulators of RXRalpha LBD.
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氘交换和质谱揭示了 RXRalpha LBD 两种合成调节剂的相互作用差异。
DOI：
10.1110/ps.073019707
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Deinzer,MaxL
中科院分区：
文献类型：
--
作者：
Yan,Xuguang;Perez,Efren;Leid,Mark;Schimerlik,MichaelI;deLera,AngelR;Deinzer,MaxL
蛋白酰胺氢/氘（H/D）交换用于比较两种拮抗剂UVI 2112和UVI 3003与激动剂9-顺式-视黄酸在与人维甲酸X受体α配体结合结构域（hRXRα LBD）同型二聚体结合后的相互作用。通过质谱分析H/D含量表明，与9-顺式-视黄酸相比，拮抗剂对整个蛋白质中的氘交换提供了更大的保护，表明蛋白质-拮抗剂复合物采用了更受限制的构象或构象系综，其中溶剂对酰胺质子的访问减少。两种拮抗剂之间的比较表明，UVI 3003在C-末端区域具有更好的保护作用，这是由于羧酸链苯环上原子产生的额外疏水相互作用。由于构象取向的差异和/或较短的羧酸链长度，其在包含肽271-278和326-330的区域内的保护性较低。在234-239片段中减少的氘交换，其中残基不涉及与配体的相互作用，在两种拮抗剂中观察到，但在9-cis-RA中未观察到。溶液中激动剂或拮抗剂占据的蛋白质的螺旋12的酰胺质子与未配体的蛋白质具有相同的氘交换速率，支持先前提出的建议，即螺旋12可以覆盖占据的结合腔，只有辅因子存在以调节其位置。
Protein amide hydrogen/deuterium (H/D) exchange was used to compare the interactions of two antagonists, UVI 2112 and UVI 3003, with that of the agonist, 9‐cis‐retinoic acid, upon binding to the human retinoid X receptor alpha ligand‐binding domain (hRXRα LBD) homodimer. Analysis of the H/D content by mass spectrometry showed that in comparison to 9‐cis‐retinoic acid, the antagonists provide much greater protection toward deuterium exchange‐in throughout the protein, suggesting that the protein–antagonist complex adopts a more restricted conformation or ensemble of conformations in which solvent accesses to amide protons are reduced. A comparison between the two antagonists shows that UVI 3003 is more protective in the C‐terminal region due to the extra hydrophobic interactions derived from the atoms in the benzene ring of the carboxylic acid chain. It was less protective within regions comprising peptides 271–278 and 326–330 due to differences in conformational orientation, and/or shorter carboxylic acid chain length. Decreased deuterium exchange‐in in the segment 234–239 where the residues do not involve interactions with the ligand was observed with the two antagonists, but not with 9‐cis‐RA. The amide protons of helix 12 of the agonist‐ or antagonist‐occupied protein in solution have the same deuterium exchange rates as the unliganded protein, supporting a suggestion made previously that helix 12 can cover the occupied binding cavity only with the cofactor present to adjust its location.