Characterization of the enzyme kinetics of EMP and HMP pathway in Corynebacterium glutamicum: reference for modeling metabolic networks

Abstract

The model of intracellular metabolic network based on enzyme kinetics parameters plays an important role in understanding the intracellular metabolic process of Corynebacterium glutamicum, and constructing such a model requires a large number of enzymological parameters. In this work, the genes encoding the relevant enzymes of the EMP and HMP metabolic pathways from Corynebacterium glutamicum ATCC 13032 were cloned, and engineered strains for protein expression with E.coli BL21 and P.pastoris X33 as hosts were constructed. The twelve enzymes (GLK, GPI, TPI, GAPDH, PGK, PMGA, ENO, ZWF, RPI, RPE, TKT, and TAL) were successfully expressed and purified by Ni2+ chelate affinity chromatography in their active forms. In addition, the kinetic parameters (Vmax, Km, and Kcat) of these enzymes were measured and calculated at the same pH and temperature. The kinetic parameters of enzymes associated with EMP and the HMP pathway were determined systematically and completely for the first time in C.glutamicum. These kinetic parameters enable the prediction of key enzymes and rate-limiting steps within the metabolic pathway, and support the construction of a metabolic network model for important metabolic pathways in C.glutamicum. Such analyses and models aid in understanding the metabolic behavior of the organism and can guide the efficient production of high-value chemicals using C.glutamicum as a host.

Styrene Production in Genetically Engineered Escherichia coli in a Two-Phase Culture

“…The bulk production of chemicals and energy using environmentally friendly systems can open new avenues to promote a sustainable society [ 1 ]. Microbial fermentation is one of the most environmentally friendly processes and is widely used to produce chemicals, fuels, and pharmaceuticals [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Over the past two decades, tools for genetic engineering and strategies for metabolic engineering and synthetic biology have drastically advanced, and researchers have enabled their ideas to be realized freely in microbial metabolic pathways [ 5 , 9 , 10 , 11 , 12 , 13 , 14 ].…”