Search results for "Protease"
showing 10 items of 463 documents
Can Experimental Electron-Density Studies be Used as a Tool to Predict Biologically Relevant Properties of Low-Molecular Weight Enzyme Ligands?
2013
The case of protease inhibitor model compounds incorporating an aziridine or epoxide ring is used to exemplify how application of experimental electron-density techniques can be used to explain the biological properties of low-molecular weight enzyme ligands. This is furthermore seen in the light of a comparison of crystal and enzyme environments employing QM/MM computations to elucidate to which extent the properties in the crystal can be used to predict behavior in the biological surrounding.
Calculation of the molecular masses of two newly synthesized thermostable enzymes isolated from thermophilic microorganisms
1995
Two thermostable enzymes synthesized by thermophilic microorganisms were isolated and purified. A thermostable beta-galactosidase was produced in a continuous fermentation process by Bacillus stearothermophilus TP 32 as an intracellular enzyme. After applying different concentration procedures the raw extract enzyme was prepurified on a Sephadex G-200 size exclusion column. The isolated beta-galactosidase fraction was then separated with HPLC on a TSK G 3000 SW size exclusion column to determine the molecular mass based on calibration curves of standard proteins. The other enzyme, a thermostable protease, was synthesized by Bacillus stearothermophilus TP 26 as an extracellular enzyme. After…
Two novel oxetane containing lignans and a new megastigmane from Paronychia arabica and in silico analysis of them as prospective SARS-CoV-2 inhibito…
2021
The chemical characterization of the extract of the aerial parts of Paronychia arabica afforded two oxetane containing lignans, paronychiarabicine A (1) and B (2), and one new megastigmane, paronychiarabicastigmane A (3), alongside a known lignan (4), eight known phenolic compounds (5–12), one known elemene sesquiterpene (13) and one steroid glycoside (14). The chemical structures of the isolated compounds were constructed based upon the HRMS, 1D, and 2D-NMR results. The absolute configurations were established via NOESY experiments as well as experimental and TDDFT-calculated electronic circular dichroism (ECD). Utilizing molecular docking, the binding scores and modes of compounds 1–3 tow…
Asymmetric One-Pot Synthesis of (3R,3aS,6aR)-Hexahydrofuro[2,3-b]furan-3-ol: A Key Component of Current HIV Protease Inhibitors
2017
A concise and efficient synthesis of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol, a key building block for several clinical and experimental HIV protease inhibitors including the highly important drug darunavir, was achieved via a one-pot procedure using furan and Cbz-protected glycol aldehyde as starting materials. A [2+2]-photocycloaddition between both reactants which can be prepared from wood-based starting materials according to the principles of xylochemistry, followed by hydrogenation and lipase-catalyzed kinetic resolution afforded the target compound in high yield and up to 99% ee.
Recent advances on application of peptide nucleic acids as a bioreceptor in biosensors development
2019
Abstract The analogs of DNA are unique biomedical tools that are broadly utilized to develop different types of biosensors. Peptide nucleic acids (PNA) are an individual and notable class of nucleic acid analogs due to their unique, novel physicochemical and biochemical characteristics, stability and resistance to nuclease and protease enzymes, significant interactions with complementary strands and remarkable hybridization attributes. Therefore, they are employed in the preparation and fabrication of various types of functional biosensors. In other words, immobilization of PNA as an appropriate diagnostic probe on the surface of electrochemical and optical converters lead to the fabricatio…
Purification of ATP synthase from beef heart mitochondria (FoF1) and co-reconstitution with monomeric bacteriorhodopsin into liposomes capable of lig…
1993
ATP synthase was isolated from beef heart mitochondria by extraction with N,N-bis-(3-D-gluconamidopropyl)deoxycholamide or by traditional cholate extraction. The enzyme was purified subsequently by ion-exchange and gel-permeation chromatographies in the presence of glycerol and the protease inhibitor diisopropylfluorophosphate. The ATP synthase consisted of 12–14 subunits and contained three tightly bound nucleotides. The co-reconstitution of crude or purified ATP synthase with monomeric bacteriorhodopsin by the method of detergent incubation of liposomes yielded proteoliposomes capable of light-driven ATP synthesis, as detected with a luciferase system for at least 30 min. The reaction was…
Translocation of enzymes into a mesoporous MOF for enhanced catalytic activity under extreme conditions
2019
Translocation of protease into mesoporous MIL-101-NH2 results in enhanced catalytic activity, excellent recyclability and tolerance to competing enzymes.
Fluorogenic Enzyme-Triggered Domino Reactions Producing Quinoxalin-2(1H)-one-based Heterocycles
2020
International audience; A simple and effective biocompatible domino reaction triggered by a model protease and leading to formation of strongly fluorescent quinoxalin-2(1H)-one N-heterocycles is described. Some positive attributes including versatility and ability to provide outstanding fluorescence "OFF-ON" responses were revealed by this work. They open the way for practical applications of this novel type of "covalent-assembly" based fluorescent probes in the fields of sensing and bioimaging. Among the myriad of synthetic transformations and catalysts currently available for concise and efficient synthesis of organic molecules, bioinspired approaches based on the use of enzymes often int…
Multiscale Simulations of SARS-CoV-2 3CL Protease Inhibition with Aldehyde Derivatives. Role of Protein and Inhibitor Conformational Dynamics in the …
2020
<p>We here investigate the mechanism of SARS-CoV-2 3CL protease inhibition by one of the most promising families of inhibitors, those containing an aldehyde group as warhead. These compounds are covalent inhibitors that inactivate the protease forming a stable hemithioacetal complex. Inhibitor 11a is a potent inhibitor that has been already tested in vitro and in animals. Using a combination of classical and QM/MM simulations we determined the binding mode of the inhibitor into the active site and the preferred rotameric state of the catalytic histidine. In the noncovalent complex the aldehyde group is accommodated into the oxyanion hole formed by the NH main chain groups of residues …
Controlled cleavage of KLH1 and KLH2 by the V8 protease from Staphylococcus aureus reassociation, electrophoretic and transmission electron microscop…
1999
The reassociation behaviour of protease V8-cleaved peptides from KLH1 and KLH2, the two hemocyanin isoforms from the giant keyhole limpet Megathura crenulata, has been studied by transmission electron microscopy of negatively stained specimens and SDS/PAGE. Reassociation of the complete mixture of protease cleavage products and of combinations of peptide fragments purified by HPLC was performed in the presence of 100 mm CaCl2 and 100 mm MgCl2 at pH 7.4, over a period of 1 to 4 weeks. The V8 protease splits KLH1 into peptide fragments containing the functional units abc, def, defg, defgh, g and h. This mixture of peptide fragments reassociated to form helical tubular polymers, with a diamete…