荔枝蒂蛀虫2个气味结合蛋白基因克隆及其与性信息素的分子对接

Cloning of two odorant binding protein genes in Conopomorpha sinensis Bradley and their molecular docking with sex pheromone components

  • 摘要: 【目的】 明确荔枝蒂蛀虫(Conopomorpha sinensis Bradley)气味结合蛋白(OBPs)在荔枝蒂蛀虫识别性信息素过程中的功能,为阐明荔枝蒂蛀虫性信息素识别的化学通讯机制提供理论依据。【方法】 基于对荔枝蒂蛀虫雌虫和雄虫的触角转录组测序结果分析,获得与性信息素识别相关的CsOBPs蛋白,采用cDNA末端快速扩增(RACE)技术克隆CsOBPs基因全长并进行生物信息学分析;通过实时荧光定量PCR检测CsOBPs基因在荔枝蒂蛀虫3日龄成虫不同组织(触角、头、胸、腹、足、翅)和时间点(00:00、04:00、08:00、12:00、16:00、20:00、24:00)的表达模式;利用AlphaFold2构建CsOBPs蛋白的三级结构模型,结合分子对接解析其与性信息素的结合能力。【结果】 克隆获得2条与性信息素识别相关的OBPs基因序列,分别命名为CsOBP1CsOBP2,通过扩增得到基因序列全长,其中,CsOBP1基因全长859 bp,编码121个氨基酸残基,蛋白分子量为14.27 kD,理论等电点为5.91;CsOBP2基因全长824 bp,编码160个氨基酸残基,蛋白分子量为18.24 kD,理论等电点为5.27。实时荧光定量PCR结果显示,CsOBP1CsOBP2基因在荔枝蒂蛀虫各组织中均有表达,且在雄虫触角中表达量最高;2个基因均在夜间高表达,其表达规律与该虫交尾行为周期基本一致。同源建模结果显示,CsOBP1和CsOBP2蛋白具有OBPs的典型结构特征,即含有6个保守的半胱氨酸残基形成的3对二硫键。分子对接分析结果显示,CsOBP1和CsOBP2蛋白与6种性信息素组分结合能介于-5.3~-9.1 kcal/mol,说明CsOBP1和CsOBP2蛋白与性信息素组分均有较强的结合力。分子动力学轨迹模拟结果显示,CsOBP1和CsOBP2蛋白与性信息素组分主要依赖范德华相互作用能和非极性溶剂自由能相结合形成稳定的复合体。【结论】 CsOBP1CsOBP2基因与性信息素识别相关,CsOBP1和CsOBP2可作为性信息素识别蛋白参与荔枝蒂蛀虫识别性信息素过程的调控。

     

    Abstract: 【Objective】 This study clarified the function of odorant binding proteins (OBPs) of Conopomorpha sinensis Bradley in the recognition of sex pheromones, which could provide theoretical basis for elucidating the chemical communication mechanism underlying sex pheromone recognition in Conopomorpha sinensis Bradley.【Method】 Based on transcriptome data from the antennae of female and male Conopomorpha sinensis Bradley,the CsOBPs proteins related to the recognition of sex pheromones were obtained, rapid amplification of cDNA end (RACE) technique was adopted to clone the full-length of CsOBPs gene and bioinformatics analysis was also conducted. The expression patterns of CsOBPs gene in different tissues (antennae, head, thorax, abdomen, leg, wing) and time points (00:00,04:00,08:00,12:00,16:00,20:00,24:00) of the 3-day-old adult of Conopomorpha sinensis Bradley were detected by real-time fluorescence quantitative PCR. The tertiary structure model of the CsOBPs protein was constructed using AlphaFold 2, and its binding ability with sex pheromones was analyzed through molecular docking.【Result】 Two sex pheromone recognition-related OBPs genes sequences,CsOBP1 and CsOBP2,were successfully cloned. The full-length gene sequences were obtained through amplification. CsOBP1 gene was 859 bp in length,encoding 121 amino acids residues with a molecular weight of 14.27 kD and theoretical isoelectric point of 5.91. CsOBP2 gene was 824 bp in length,encoding 160 amino acids residues with a molecular weight of 18.24 kD and theoretical isoelectric point of 5.27. Real-time fluorescence quantitative PCR analysis revealed that, both genes were expressed in various tissues of Conopomorpha sinensis Bradley, with the highest expression level in male antennae. Additionally,the expression of the two genes peaked at night,which was consistent with the mating behavior rhythm of this pest. The results of homology modeling showed that CsOBP1 and CsOBP2 proteins possessed the typical characteristics of OBPs,containing three pairs of disulfide bonds formed by six conserved cysteine residues. The results of molecular docking indicated that CsOBP1 and CsOBP2 proteins had strong binding ability for six sex pheromone components with binding energies ranging from -5.3 to -9.1 kcal/mol. Molecular dynamics trajectory simulation results indicated that CsOBP1 and CsOBP2 proteins formed stable complexes with sex pheromone components primarily through van der Waals interaction energy and nonpolar solvation energy.【Conclusion】 CsOBP1 and CsOBP2 genes are associated with sex pheromone recognition, and CsOBP1 and CsOBP2 can act as sex pheromone binding proteins involved in regulating the process of sex pheromone recognition in Conopomorpha sinensis Bradley.

     

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