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化学感受蛋白是一类存在于昆虫化学感受器中的可溶性蛋白,被认为与昆虫识别外界化学信息有关。本研究使用pGEX-4T-1表达载体在BL21(DE3)异源表达系统中表达中红侧沟茧蜂Microplitis mediator化学感受蛋白MmedCSP1,并通过亲和层析法纯化得到去表达标签的MmedCSP1;使用bis-ANS作为荧光配基,在荧光分光光度计上研究它与50种气味标样的结合特征,从而得到此类化学感受蛋白在中红侧沟茧蜂嗅觉识别中识别气味的种类。结果表明:MmedCSP1只能与水杨酸甲酯、戊烷、罗勒烯、β-紫罗兰酮、3,4-二甲基苯甲醛、2-己酮和叶醇结合。但只有脂类化合物β-紫罗兰酮能在浓度为1mmol/L下将bis-ANS从MmedCSP1中替换50%,β-紫罗兰酮与MmedCSP1的结合常数为16.89μmol/L。这些结果提示MmedCSP1参与中红侧沟茧蜂对水杨酸甲酯、戊烷、罗勒烯、β-紫罗兰酮、3,4-二甲基苯甲醛、2-己酮和叶醇等气味的识别过程,且在不同气味中的识别过程中对于气味的运输能力有差异。
Chemosensitive proteins, a class of soluble proteins found in insect chemoreceptors, are thought to be involved in insect identification of outside chemical information. In this study, MmedCSP1 was expressed in the BL21 (DE3) heterologous expression system using the pGEX-4T-1 expression vector and purified by affinity chromatography to obtain a labeled MmedCSP1. bis-ANS as a fluorescent ligand to study its binding characteristics with 50 kinds of odor standards on a fluorescence spectrophotometer, so as to obtain the kind of chemical sensitivities for identifying odor in the olfactory recognition of Artichoke beetles. The results showed that MmedCSP1 could only combine with methyl salicylate, pentane, ocimene, β-ionone, 3,4-dimethylbenzaldehyde, 2-hexanone and phytol. However, only the β-ionone lipid compound could replace 50% of bis-ANS from MmedCSP1 at a concentration of 1 mmol / L, and the binding constant of β-ionone to MmedCSP1 was 16.89 μmol / L. These results suggest that MmedCSP1 participates in the identification of the odor of M. crassipes on the odor of methyl salicylate, pentane, ocimene, beta-ionone, 3,4-dimethylbenzaldehyde, 2-hexanone and phytol Process, and there is a difference in odors’ ability to transport odor during identification.