SAR of non-hydrolysable analogs of pyridoxal 5'-phosphate against low molecular weight protein tyrosine phosphatase isoforms.

Kinases and phosphatases are key enzymes in cell signal transduction pathways. Imbalances in these enzymes have been linked to numerous disease states ranging from cancer to diabetes to autoimmune disorders. The two isoforms (IFA and IFB) of Low Molecular Weight Protein Tyrosine Phosphatase (LMW-PTP) appear to play a role in these diseases. Pyridoxal 5'-phosphate (PLP) has been shown to act as a potent but, impractical micromolar inhibitor for both isoforms. In this study, a series of non-hydrolysable phosphonate analogs of PLP were designed, synthesized and tested against the two isoforms of LMW-PTP. Assay results demonstrated that the best inhibitor for both isoforms was compound 5 with a Kis of 1.84 µM (IFA) and 15.6 µM (IFB). The most selective inhibitor was compound 16, with a selectivity of roughly 370-fold for IFA over IFB.

Alginate-Encapsulated Bacteria for the Treatment of Hypersaline Solutions in Microbial Fuel Cells.

A microbial fuel cell (MFC) based on a new wild-type strain of Salinivibrio sp. allowed the self-sustained treatment of hypersaline solutions (100 g L-1 , 1.71 m NaCl), reaching a removal of (87±11) % of the initial chemical oxygen demand after five days of operation, being the highest value achieved for hypersaline MFC. The degradation process and the evolution of the open circuit potential of the MFCs were correlated, opening the possibility for online monitoring of the treatment. The use of alginate capsules to trap bacterial cells, increasing cell density and stability, resulted in an eightfold higher power output, together with a more stable system, allowing operation up to five months with no maintenance required. The reported results are of critical importance to efforts to develop a sustainable and cost-effective system that treats hypersaline waste streams and reduces the quantity of polluting compounds released.