Alpha-1 antitrypsin deficiency (A1ATD) is an autosomal recessive disease characterized by low plasma levels of A1AT, a serine protease inhibitor representing the most abundant circulating antiprotease normally present at plasma levels of 1-2 g/L. The dominant clinical manifestations include predispositions to early onset emphysema due to protease/antiprotease imbalance in distal lung parenchyma and liver disease largely due to unsecreted polymerized accumulations of misfolded mutant A1AT within the endoplasmic reticulum of hepatocytes. Since 1987, the only FDA licensed specific therapy for the emphysema component has been infusions of A1AT purified from pooled human plasma at the 2020 cost of up to US $200,000/year with the risk of intermittent shortages.
View Article and Find Full Text PDFProtein engineering to alter recognition underlying ligand binding and activity has enormous potential. Here, ligand binding for Escherichia coli phosphoenolpyruvate carboxykinase (PEPCK), which converts oxaloacetate into CO and phosphoenolpyruvate as the first committed step in gluconeogenesis, was engineered to accommodate alternative ligands as an exemplary system with structural information. From our identification of bicarbonate binding in the PEPCK active site at the supposed CO binding site, we probed binding of nonnative ligands with three oxygen atoms arranged to resemble the bicarbonate geometry.
View Article and Find Full Text PDFA serendipitous five-step cascade of rhodium vinylcarbenoids with aminochalcones enables a unique synthetic approach to highly functionalized tri- and tetra-cyclic quinolines. The cascade reaction begins with the insertion of aminochalcone nitrogen into rhodium vinylcarbenoids followed by intramolecular aldol cyclization to provide a substituted indoline intermediate that undergoes an oxy-Cope rearrangement to provide a 9-membered azacycle, which then rearranges to the functionalized quinoline through an intramolecular aldol/dehydration sequence. With a catalyst loading as low as 0.
View Article and Find Full Text PDFCA II makes a good PET: Discovering positron emission tomography (PET) probes with high target affinities is challenging. PET probe discovery using in situ click chemistry uses (19) F-bearing fragments as (18) F surrogates. This ensures that the lead hits and PET probes have equivalent chemical or biological characteristics, making PET probe discovery predictable and reliable.
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