Abstract：
Protein adducts are important biological targets for traceability of organophosphorus nerve agents (OPNAs). Currently, the recognized biomarkers that can be used in actual samples in the field of chemical forensics only include Y411 in albumin and the active nonapeptide in butyrylcholinesterase (BChE). To explore stable and reliable protein adducts and increase the accuracy of OPNAs traceability further, we gradually expanded OPNAs-albumin adducts based on single and group adduct collection. Several stable peptides were found via LC-MS/MS analysis in human serum albumin (HSA) exposed to OPNAs in a large exposure range. These adducts were present in HSA samples exposed to OPNAs of each concentration, which provided data support for the reliability and stability of using adducts to trace OPNAs. Meanwhile, the formation mechanism of OPNAs-cysteine adduct was clarified via computer simulations. Then, these active sites found and modified peptides were used as raw materials for progressive expansion of albumin adducts. We constructed an OPNAs-HSA adducts group, in which a specific agent is the exposure source, and three or more active peptides constitute data sets for OPNAs traceability. Compared with single or scattered protein adducts, the OPNAs-HSA adduct group improves OPNAs identification by mutual verification using active peptides or by narrowing the identity range of the exposure source. We also determined the minimum detectable concentration of OPNAs for the adduct group. Two or more peptides can be detected when there is an exposure of 50 times the molar excess of OPNAs in relation to HSA. This improved the accuracy of OPNAs exposure and identity confirmation. A collection of OPNAs-albumin adducts was also examined. The collection was established by collecting, classifying, and integrating the existing albumin adducts according to the species to which each albumin belongs, the types of agents, and protease. This method can serve as a reference for discovering new albumin adducts, characteristic phosphonylated peptides, and potential biomarkers. In addition, to avoid a false negative for OPNAs traceability using albumin adducts, we explored OPNAs-cholinesterase adducts because cholinesterase is more reactive with OPNAs than albumin. Seven active peptides in red blood cell acetylcholinesterase (RBC AChE) and serum BChE can assist in OPNAs exposure and identity confirmation.
摘要：
蛋白质加合物是有机磷神经毒剂（OPNAs）可追溯性的重要生物学靶标。目前,可用于化学法医学领域实际样本的公认生物标志物仅包括白蛋白中的Y411和丁酰胆碱酯酶(BChE)中的活性非肽.为了探索稳定可靠的蛋白质加合物，进一步提高OPNAs可追溯性的准确性，我们在单一和组加合物收集的基础上逐步扩展了OPNAs-白蛋白加合物。通过LC-MS/MS分析在大暴露范围内暴露于OPNA的人血清白蛋白（HSA）中发现了几种稳定的肽。这些加合物存在于暴露于每种浓度的OPNA的HSA样品中，为使用加合物跟踪OPNA的可靠性和稳定性提供数据支持。同时,通过计算机模拟阐明了OPNAs-半胱氨酸加合物的形成机理。然后，这些发现的活性位点和修饰的肽被用作逐渐扩增白蛋白加合物的原料。我们建立了一个OPNAs-HSA加合物组,其中特定的试剂是暴露源，和三个或更多的活性肽构成用于OPNA可追溯性的数据集。与单一或分散的蛋白质加合物相比，OPNAs-HSA加合物组通过使用活性肽的相互验证或通过缩小暴露源的身份范围来改善OPNAs的鉴定。我们还确定了加合物基团的OPNA的最小可检测浓度。当存在相对于HSA的OPNA的50倍摩尔过量的暴露时,可以检测到两种或更多种肽。这提高了OPNA暴露和身份确认的准确性。还检查了OPNA-白蛋白加合物的集合。收集是通过收集建立的，分类，并根据每种白蛋白所属的物种整合现有的白蛋白加合物，代理的类型，和蛋白酶。该方法可为发现新的白蛋白加合物提供参考。特征性磷酸化肽，和潜在的生物标志物。此外,为了避免使用白蛋白加合物对OPNAs可追溯性的假阴性，我们探讨了OPNAs-胆碱酯酶加合物,因为胆碱酯酶与OPNAs的反应性比白蛋白强.红细胞乙酰胆碱酯酶（RBCAChE）和血清BChE中的7种活性肽可以帮助OPNA暴露和身份确认。
