KS
Kim Shortall
  • Ph. D. Candidate, University of Limerick Limerick
研究方向
  • Biochemistry
Expression, Purification, and in vitro Enzyme Activity Assay of a Recombinant Aldehyde Dehydrogenase from Thermus thermophilus, using an Escherichia coli host
使用大肠杆菌宿主的嗜热栖热菌重组醛脱氢酶的表达、纯化和体外酶活性测定
作者:Kim Shortall, Edmond Magner and Tewfik Soulimane日期:05/05/2022,浏览量:2005,Q&A: 0

Based on previous in-depth characterisation, aldehyde dehydrogenases (ALDH) are a diverse superfamily of enzymes, in terms of both structure and function, present in all kingdoms of life. They catalyse the oxidation of an aldehyde to carboxylic acid using the cofactor nicotinamide adenine dinucleotide (phosphate) (NAD(P)+), and are often not substrate-specific, but rather have a broad range of associated biological functions, including detoxification and biosynthesis. We studied the structure of ALDHTt from Thermus thermophilus, as well as performed its biochemical characterisation. This allowed for insight into its potential substrates and biological roles.


In this protocol, we describe ALDHTt heterologous expression in E. coli, purification, and activity assay (based on Shortall et al., 2021). ALDHTt was first copurified as a contaminant during caa3-type cytochrome oxidase isolation from T. thermophilus. This recombinant production system was employed for structural and biochemical analysis of wild-type and mutants, and proved efficient, yielding approximately 15–20 mg/L ALDHTt. For purification of the thermophilic his-tagged ALDHTt, heat treatment, immobilized metal affinity chromatography (IMAC), and gel filtration chromatography were used. The enzyme activity assay was performed via UV-Vis spectrophotometry, monitoring the production of reduced nicotinamide adenine dinucleotide (NADH).



Graphical abstract:



Flow chart outlining the steps in ALDHTt expression and purification, highlighting the approximate time required for each step.