Biosensors based on microbial cells have been developed to monitor environmental pollutants. These biosensors serve as inexpensive and convenient alternatives to the conventional lab based instrumental analysis of environmental pollutants. Small monomeric naturally occurring fluorescent proteins (fp) can be exploited by converting them as small biosensing devices for biomedical and environmental applications. Moreover, they can withstand exposure to denaturants, high temperature, and a wide pH range variation. The current study employs newly identified novel fluorescent protein HriGFP from Hydnophora rigida to detect environmental contaminants like heavy metals and organo-phosphorous (pesticide) compounds such as methyl parathion. The HriGFP was initially tested or its expression in bacterial systems (Gram positive and Gram negative) and later on for its biosensing capability in E coli (BL21DE3) for detection of heavy metals and methyl parathion was evaluated. Our results indicated the discrete and stable expression of HriGFP and a profound fluorescent quenching were observed in the presence of heavy metals (Hg, Cu, As) and methyl parathion. Structural analysis revealed heavy metal ions binding to HriGFP via amino acid residues. In-silico-analysis further revealed strong interaction via hydrogen bonds between methyl parathion phosphate oxygen atoms and the amino group of Arg119 of HriGFP. This study implies that HriGFP can act as a biosensor for detecting harmful carcinogenic pesticide like methyl parathion in water resources in the vicinity of heavily pesticide impregnated agricultural lands and heavy metal contaminated water bodies around industrial areas.

中文翻译：

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HriGFP新型荧光蛋白：表达和应用。

已经开发了基于微生物细胞的生物传感器来监测环境污染物。这些生物传感器可作为传统的基于实验室的环境污染物分析仪器的廉价便捷的替代品。天然的小单体荧光蛋白（fp）可以通过将其转换为用于生物医学和环境应用的小型生物传感设备加以利用。此外，它们可以承受变性剂，高温和广泛的pH范围变化的影响。当前的研究采用了刚鉴定过的新的刚性海豚的荧光蛋白HriGFP来检测环境污染物，例如重金属和有机磷（农药）化合物，例如甲基对硫磷。最初测试了HriGFP或其在细菌系统（革兰氏阳性和革兰氏阴性）中的表达，然后评估了其在大肠杆菌（BL21DE3）中检测重金属和甲基对硫磷的生物传感能力。我们的结果表明，在存在重金属（Hg，Cu，As）和甲基对硫磷的情况下，HriGFP的表达稳定且离散，并且荧光猝灭程度很高。结构分析表明，重金属离子通过氨基酸残基与HriGFP结合。硅内分析进一步揭示了甲基对硫磷磷酸氧原子与HriGFP Arg119氨基之间的氢键之间存在强相互作用。