Kinetic values of purified and displayed G6PDH [Glucose-6-phosphate dehydrogenase]

Range Table - link
Organism Bacteria Escherichia coli
Reference Schüürmann J et al., Autodisplay of glucose-6-phosphate dehydrogenase for redox cofactor regeneration at the cell surface. Biotechnol Bioeng. 2017 Aug114(8):1658-1669. doi: 10.1002/bit.26308 p.1662 table IPubMed ID28401536
Method P.1661 right column 2nd paragraph: "For comparison, a plasmid for intracellular expression of the G6PDH was created by inserting the dehydrogenase encoding DNA sequence into the pET11d backbone via In-Fusion cloning. Addition of a coding sequence for a C-terminal 6xHis tag yielded the plasmid pJS011D, which was used for expression of a His-tagged variant of the G6PDH. Purification resulted in a pure protein (Fig. 2B) with concentrations of 0.8 mg/mL. The kinetic parameters of the purified G6PDH are listed in Table I. With KM values of 0.13 mM for NADP+ and 0.22 mM for G6P, they were similar to previously published data (KM NADP+: 0.068 mM, KM G6P: 0.34 mM) (Schindler and Schlegel, 1969)."
Comments P.1663 left column bottom paragraph: "For further characterization of the whole cell biocatalyst, the turnover frequency (TOF, Kcat) was calculated (Table I). Two assumptions were made. First, a value of 7 × 10^8 cells per milliliter was taken for the number of E. coli cells at an OD578 1 as reported before (Sezonov et al., 2007). And second, the value for enzyme molecules per cell of 26,467 was taken from the densitometric analysis of the outer membrane isolations. Thus, Kcat with 19.0/s of the surface displayed enzyme is rather a rough approximation. Nevertheless, the calculated Kcat value was only about 1.7-fold lower than the Kcat of the purified enzyme (32.5/s) and thus remarkably similar. Hence, most likely, the enzyme was completely active at the cell surface."
Entered by Uri M
ID 114106