Molecular basis of hemoglobin binding and heme removal in .

To successfully mount infections, nearly all bacterial pathogens must acquire iron, a key metal cofactor that primarily resides within human hemoglobin. causes the life-threatening respiratory disease diphtheria and captures hemoglobin for iron scavenging using the surface-displayed receptor HbpA. Here, we show using X-ray crystallography, NMR, and in situ binding measurements that selectively captures iron-loaded hemoglobin by partially ensconcing the heme molecules of its α subunits.

Structural, biophysical, and biochemical insights into C-S bond cleavage by dimethylsulfone monooxygenase.

Sulfur is an essential element for life. Bacteria can obtain sulfur from inorganic sulfate; but in the sulfur starvation-induced response, employ two-component flavin-dependent monooxygenases (TC-FMOs) from the and operons to assimilate sulfur from environmental compounds including alkanesulfonates and dialkylsulfones. Here, we report binding studies of oxidized FMN to enzymes involved within the enzymatic pathway responsible for converting dimethylsulfone (DMSO) to sulfite.

Nickel/Iridium Metallaphotoredox Catalysis for Allylic C-H Bond Arylation of -Allyl Heterocycles.

Despite conceptual breakthroughs in dual photoredox- and nickel-catalyzed arylation of radicals, the approach remains largely limited to localized C-centered radicals. Here, we extend it to allylic radicals, focusing on -allyl heterocycles. Using [Ir(dF(CF)ppy)(dtbbpy)]PF and NiCl(dtbbpy) under visible light, we achieve regioselective γ-amino radical arylation, yielding enamines in good yields.

Rhodium(i)-catalyzed cascade C(sp)-H bond alkylation - amidation of anilines: phosphorus as traceless directing group.

We introduce a versatile Rh(i)-catalyzed cascade reaction, combining C(sp)-H bond functionalization and amidation between -arylphosphanamines and acrylates. This innovative approach enables the rapid synthesis of dihydroquinolinone scaffolds, a common heterocycle found in various pharmaceuticals. Notably, the presence of the phosphorus atom facilitates the aniline -C(sp)-H bond activation prior to N-P bond hydrolysis, streamlining one-pot intramolecular amidation.

Antibacterial and Cytocompatible pH-Responsive Peptide Hydrogel.

A short peptide, FHHF-11, was designed to change stiffness as a function of pH due to changing degree of protonation of histidines. As pH changes in the physiologically relevant range, G' was measured at 0 Pa (pH 6) and 50,000 Pa (pH 8). This peptide-based hydrogel is antimicrobial and cytocompatible with skin cells (fibroblasts).