蓖麻内源防御肽的MALDI-MSI方法及溯源应用研究

国际范围内,蓖麻毒素、蓖麻籽粗提物以及蓖麻籽等均为蓖麻毒素信件的潜在来源,屡屡引发公共安全威胁.因此,蓖麻籽产地溯源至关重要.该研究选择高丰度、低毒性的蓖麻内源性防御肽(RCB),系统探讨优化了冷冻切片制备、基质喷雾等条件,首次建立了RCB 的基质辅助激光解吸电离-质谱成像(MALDI-MSI)方法.选择四川、山西为中...

MALDI-Mass Spectrometry Imaging of Endogenous Defensive Peptides and Its Application in Tracing Origins of Castor Beans

Castor bean,crude extract and ricin are potential sources of the"ricin letter"events,which have posed a great threat on public security worldwide.Investigations on tracing the geographic origins of castor beans are of urgent need in case of accidental food ingestion,environmental exposure and deliberate poisoning.Here,based on a thorough optimization of section preparation,matrix application and several key parameters,a novel,sensitive and convenient matrix assisted laser desorption ionization-mass spectrometry imaging(MALDI-MSI)method was firstly established for three endogenous defensive Ricinus communis biomarkers(RCB)with high abundance and low toxicity.Using the mature castor beans obtained from representative geographic origins,Shanxi province in North China and Sichuan province in South China,the abundance and spatial,longitudinal distributions of three RCBs in the castor bean sections were elucidated.Results showed that the RCBs were mainly distributed in the endosperm and embryo of the mature seeds,which exerted distinct abundance difference between Shanxi?s and Sichuan?s.Furthermore,the reconstructed 3 D MSI model based on the longitudinal visualization in half of a Shanxi?s seed revealed different abundances of RCBs in main organs of castor beans,consistent with the 2 D MSI results.Moreover,the three RCBs all belonged to the component of the highest contribution degree in the non-targeted data-mining analysis.It is suggested that a whole set of RCBs 1-3 should be integratedly regarded as the traceable biomarkers for different geographical location.The low-cytotoxic effect of RCBs assured a safe and reliable alternative way for retrospective analysis.This new MSI strategy exhibits its high sensitivity and favorable applicability in deep insight to unravel the role of defensive peptides biomarkers in intoxication identification,and could timely respond to food and environment-sourced hazard emergencies.