Recently two new papers were published:
- Low affinity uniporter carrier proteins can increase net substrate uptake rate by reducing efflux by Evert Bosdriesz, Meike T Wortel, Jurgen R Haanstra, Marijke J Wagner, Pilar Torre Cortés and Bas Teusink
- Metabolite Depletion Affects Flux Profiling of Cell Lines by Avlant Nilsson, Jurgen R. Haanstra, Bas Teusink and Jens Nielsen
In the first paper we compare and test different hypotheses for the existence of low affinity uniporters, in addition to high-affinity ones. Our new model-driven hypothesis shows that a low affinity glucose transporter would experience less inhibition by intracellular glucose and this would give a higher nett uptake rate. However, due to the intimate link between glucose perception and metabolism, direct experimental proof for this hypothesis remained inconclusive. Still, our theoretical results provide a novel reason for the presence of low-affinity transport system.
In the second paper (a commentary) we show that care should be taken with calculating fluxes from long incubation experiments. Over time, some metabolites deplete and this will affect (calculation of) fluxes