Sequence and Solution Effects on the Prevalence of d-Isomers Produced by Deamidation.
Sequence and Solution Effects on the Prevalence of d-Isomers Produced by Deamidation.
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DOI：
10.1021/acschembio.7b00686
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发表时间：
2017-11-17
影响因子：
4
通讯作者：
Julian RR
中科院分区：
文献类型：
--
作者：
Riggs DL;Gomez SV;Julian RR
天冬酰胺的脱酰胺是一种自发的、不可逆的翻译后修饰，与越来越多的人类疾病相关。虽然脱酰胺作用普遍存在，但它往往被忽视，因为它代表了相对较小的化学变化。这种修饰的结构和功能表征是复杂的，因为天冬酰胺的脱酰胺产生四种异构形式的天冬氨酸。在本文中，自由基定向解离（RDD）结合质谱法用于鉴定和定量经历各种脱酰胺条件的一系列模型肽中的所有四种异构体。尽管一级序列显著影响脱酰胺速率，但它对产物异构体的相对比例几乎没有影响。此外，氨的添加可用于增加脱酰胺的速率而不显著干扰异构体群体。相反，外部因素如缓冲液条件和温度改变产物分布，但对脱酰胺速率的影响较小。引人注目的是，发现常见的实验室和生物学显著的碳酸氢盐缓冲液强烈促进外消旋化，产生增加量的d-Asp和d-isoAsp。脱酰胺后的这些结果对人类衰老具有广泛的影响，在开发基于蛋白质的治疗方法时应予以考虑。
Deamidation of asparagine is a spontaneous and irreversible post-translational modification associated with a growing list of human diseases. While pervasive, deamidation is often overlooked because it represents a relatively minor chemical change. Structural and functional characterization of this modification is complicated because deamidation of asparagine yields four isomeric forms of Asp. Herein, radical directed dissociation (RDD), in conjunction with mass spectrometry, is used to identify and quantify all four isomers in a series of model peptides that were subjected to various deamidation conditions. Although primary sequence significantly influences the rate of deamidation, it has little impact on the relative proportions of the product isomers. Furthermore, the addition of ammonia can be used to increase the rate of deamidation without significantly perturbing isomer populations. Conversely, external factors such as buffer conditions and temperature alter product distributions but exhibit less dramatic effects on the deamidation rate. Strikingly, the common laboratory and biologically significant bicarbonate buffer is found to strongly promote racemization, yielding increased amounts of d-Asp and d-isoAsp. These outcomes following deamidation have broad implications in human aging and should be considered during the development of protein-based therapeutics.
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影响因子：
4.9
作者：
Ly, Tony;Zhang, Xing;Julian, Ryan R.
通讯作者：
Julian, Ryan R.
影响因子：
3.5
作者：
Liu S;Moulton KR;Auclair JR;Zhou ZS
通讯作者：
Zhou ZS
影响因子：
3.9
作者：
Lindner, H;Helliger, W
通讯作者：
Helliger, W
通过离子迁移率光谱法含有（D）氨基酸的（D） - 氨基酸的位点特异性表征。
影响因子：
7.4
作者：
Jia, Chenxi;Lietz, Christopher B.;Yu, Qing;Li, Lingjun
通讯作者：
Li, Lingjun
影响因子：
2.1
作者：
Hood, Christina A.;Fuentes, German;Park, Jae H.
通讯作者：
Park, Jae H.