金属螯合蛋白异源表达提高E.coli对镉的生物吸附能力:修复潜力和潜在机制
Enhancing cadmium biosorption capacity in E.coli through heterologous expression of metal-chelating proteins:Insights into bioremediation potential and mechanisms
武晨 1吴玉俊 1易盛炜 1李峰1
作者信息
- 1. College of Environment and Resources,Xiangtan University,Xiangtan 411105,China;Hunan Provincial University Key Laboratory for Environmental and Ecological Health,Xiangtan University,Xiangtan 411105,China;Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants,Xiangtan University,Xiangtan 411105,China
- 折叠
摘要
镉(Cd)作为一种生物非必需的有毒重金属,通过自然排放或人类活动进入环境,对人类健康构成威胁.在微生物中高效表达金属螯合蛋白(MCP)可以增强生物对Cd的吸附能力.本研究构建了mcp基因编码的MCP的异源表达体系(GEM01),探究了其对Cd的吸附效果和潜在机制.结果表明,Cd2+调控GEM01中mcp基因丰度,mcp基因的表达增加了Cd2+的生物吸附能力(8.09 mg/g,比对照组高2.32倍).在GEM01自溶过程中Cd2+的保留率为87.87%.荧光光谱和分子动力学模拟表明了Cd2+与MCP之间存在较强的相互作用且Cd2+影响了MCP的二级结构.FT-IR证明了MCP中的官能团(如羧基、甲基和亚甲基)参与了MCP与Cd2+的相互作用.分子对接进一步表明MCP蛋白表面的一些极性和亲水残基(如天冬酰胺、谷氨酰胺、丝氨酸和组氨酸)通过静电引力与Cd2+结合.本研究为MCP介导的Cd2+生物修复提供了新的见解,为微生物修复重金属污染提供了基因资源.
Abstract
Cadmium(Cd)is a biologically non-essential and toxic heavy metal that enters the environment through natural emissions or anthropogenic activities,posing threats to human health.The efficient expression of metal-chelating proteins(MCP)in microorganisms can enhance microbial remediation of Cd.In this study,a heterologous expression system(GEM01)of MCP encoded by the mcp gene in E.coli was constructed,and the adsorption effect and potential mechanism on Cd were explored.The results indicated that Cd2+significantly enhanced the abundance of mcp gene in GEM01,thus increasing the Cd2+biosorption capacity(8.09 mg/g,2.32 times higher than the control).The retention of Cd2+during the autolysis of GEM01 was 87.87%.Fluorescence spectroscopy and molecular dynamics simulations demonstrated that there was a strong interaction between Cd2+and MCP.FT-IR demonstrated that some functional groups(e.g.,carboxyl group and methyl group)in MCP were involved in the interaction between MCP and Cd2+.Molecular docking further demonstrated that polar and hydrophilic residues(e.g.,aspartic acid,glutamic acid,serine,and histidine)on the surface of MCP bound to Cd2+via electrostatic attraction.These findings offer new insights into Cd2+bioremediation by MCP and genetic resources for microbial remediation of heavy metal pollution.
关键词
镉/mcp基因/金属螯合蛋白/相互作用/微生物修复Key words
cadmium/mcp gene/metal chelating protein/interaction/microbial remediation引用本文复制引用
基金项目
国家自然科学基金(22176161)
国家自然科学基金(42307521)
National Natural Science Foundation of China-Hunan Joint Fund(U21A20293)
中国博士后科学基金(2023M742934)
Hunan Provincial Innovation Foundation for Postgraduate,China(CX20220599)
Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province()
出版年
2024
NETL
NSTL
万方数据