Validating the inhibitory effects of d- and l-serine on the enzyme activity of d-3-phosphoglycerate dehydrogenases that are purified from Pseudomonas aeruginosa Escherichia coli and human colon

摘要

BackgroundWe previously demonstrated that the serA gene is associated with bacterial pathogenicity, including bacterial penetration through the Caco-2 cell monolayers, bacterial motility, bacterial adherence, and fly mortality. l-Serine is known to inhibit the d-3-phosphoglycerate dehydrogenase (PGDH) activity of the SerA protein, and it significantly reduced the bacterial pathogenicity as described above. We also demonstrated that in a PGDH assay using crude extracts isolated from overnight cultures of E. coli overexpressing the P. aeruginosa serA gene, l-serine inhibited the PGDH activity of the SerA protein. The basal PGDH activity of the negative control strain was high, presumably due to contamination of unknown proteins in the crude extracts. Therefore, to further confirm the direct inhibition of PGDH activity of P. aeruginosa SerA by l-serine, we purified and characterized the PGDH from P. aeruginosa and compared it with the previously characterized PGDHs from E. coli, and the human colon as controls.