muramidase and coumarin

Amyloid aggregates of proteins are one of the most abundant and important naturally occurring self-associated assemblies. Formation of poly/peptide amyloid aggregates is also associated with the widely spread diseases, so called amyloidosis, which include Alzheimer's disease, diabetes mellitus and lysozyme amyloidosis. These disorders are still incurable and novel therapeutical approaches are focused on using small molecules for inhibition of amyloid aggregation. We have observed effect of three structurally distinct groups of tacrine/acridone - coumarin heterodimers on hen egg white (HEW) lysozyme fibrillization in vitro. The ability of heterodimers to interfere with lysozyme amyloid aggregation was examined using Thioflavin T fluorescence assay, atomic force microscopy and docking method. The obtained data suggest that inhibitory effect of heterodimers on lysozyme fibrillization depends on their composition. We have shown that tacrine-coumarin heterodimers with alkylenediamine linker are the most effective inhibitors of lysozyme fibrillization. The inhibitory activities were quantified through IC

Topics: Amyloid; Coumarins; Humans; Microscopy, Atomic Force; Muramidase; Tacrine

Self-healing (SH) poly(lactic-co-glycolic acid) (PLGA) microspheres are a unique class of functional biomaterials capable of microencapsulating process-sensitive proteins by simple mixing and heating the drug-free polymer in aqueous protein solution. Drug-free SH microspheres of PLGA 50/50 with percolating pore networks of varying porosity (ϵ = 0.49-73) encapsulate increasing lysozyme (≈1 to 10% w/w) with increasing ϵ, with typically ≈20 to 25% pores estimated accessible to entry by the enzyme from the external solution. Release kinetics of lysozyme under physiological conditions is continuous over more than two weeks and most strongly influenced by ϵ and protein loading before reaching a lag phase until 28 d at the study completion. Recovered enzyme after release is typically predominantly monomeric and active. Formulations containing acid-neutralizing MgCO3 at ≥ 4.3% exhibit >97% monomeric and active protein after the release with full mass balance recovery. Hence, control of SH polymer ϵ is a key parameter to development of this new class of biomaterials.

Topics: Animals; Biocompatible Materials; Cattle; Coumarins; Drug Compounding; Enzyme Assays; Kinetics; Lactic Acid; Magnesium; Microscopy, Electron, Scanning; Microspheres; Molecular Weight; Muramidase; Particle Size; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Porosity; Serum Albumin, Bovine; Water

Topics: Animals; Cattle; Coumarins; Drug Compounding; Kinetics; Lactic Acid; Macromolecular Substances; Muramidase; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Serum Albumin, Bovine; Solvents; Temperature; Trehalose

A simple and unique construction of a coumarin fluorophore on a prey protein has been achieved by sequential photoreactions using a nonfluorescent bait protein. The bait protein was first modified with a novel diazirine-based photo-cross-linker containing an o-hydroxycinnamoyl unit. The strategy involves two wavelength-dependent photoreactions: photolysis of the diazirine group and E to Z photoisomerization of the cinnamoyl group. The cross-linked interacting partners were cleaved by the consecutive steps of photoisomerization and thermal lactonization accompanied with the creation of a coumarin derivative on the prey protein as a fluorescent tag. Finally, the methodology was successfully applied for coumarin labeling of antilysozymes expressed on living B cells by using photoactivatable lysozymes.

Topics: Animals; Antibodies; Coumarins; Fluorescent Dyes; Mice; Muramidase; Photochemical Processes; Proteins; Spectrometry, Fluorescence