Search results for "peptidases"
showing 9 items of 319 documents
Parathyroid hormone-related peptide and 8701-BC breast cancer cell growth and invasion in vitro: evidence for growth-inhibiting and invasion-promotin…
1995
It has been previously reported that 8701-BC cells, derived from a primary carcinoma of the breast, constitutively express parathyroid hormone-related peptide (PTHrP) gene and that N-terminal PTHrP immunoreactivity can be found in cell medium. Here we have firstly measured immunoreactive PTHrP in 8701-BC cell medium using antibodies raised against midregion and C-terminal fragments, and also demonstrated the expression of PTH/PTHrP receptor by 8701-BC cells. Secondly, we have examined the role, if any, elicited by diverse PTHrP domains on 8701-BC cell proliferation, and invasive behaviour in vitro related to production of extracellular proteolytic enzymes. Our data show that PTHrP [1-34], a…
Substrate specificity screening of oat (Avena sativa) seeds aminopeptidase demonstrate unusually broad tolerance in S1 pocket.
2012
Aminopeptidases are proteolytic enzymes that remove one amino acid at a time from N-terminus of peptidic substrates. In plants, inhibitors of aminopeptidases can find potential applications in agriculture as herbicides. In this report we have used a library of fluorogenic derivatives of natural and unnatural amino acids for substrate specificity profiling of oat (Avena sativa) aminopeptidase. Interestingly, we have found that this enzyme recognizes effectively among the natural amino acids basic residues like Arg and Lys, hydrophobic Phe, Leu and Met, but also to some extent acidic residues Asp and Glu. In the case of unnatural amino acids hydrophobic residues (hPhe and hCha) and basic hArg…
Synthesis and Molecular Modeling Studies of Derivatives of a Highly Potent Peptidomimetic Vinyl Ester as Falcipain-2 Inhibitors
2012
Herein we report the synthesis of a set of constrained peptidomimetics endowed with an electrophilic vinyl ester warhead and structurally related to a previously identified lead compound, a potent and irreversible inhibitor of falcipain-2 (FP-2). FP-2 is the main hemoglobinase of the malaria parasite P. falciparum. The new compounds were evaluated for their inhibition against FP-2, and the results were rationalized on the basis of docking experiments. These studies underscore the pivotal role of both the ester function at the P1' site and the trifluoromethyl group of the P3 side chain in determining the correct orientation of the Michael acceptor warhead in the catalytic site, and as a cons…
Influence of bioremediation stimulators in soil on development of oat seedlings (Avena sativa) and their aminopeptidase activity
2015
Dobór technik bioremediacji jest bardzo ważny w oczyszczaniu gleby skażonej substancjami ropopochodnymi, która ma być wykorzystywanej rolniczo. Prezentowane wyniki wskazują, że na rozwój siewek owsa większy wpływ ma stosowana metoda bioremediacji niż poziom zanieczyszczenia węglowodorami. Z zastosowanych technik najbardziej przyjazne dla wegetacji owsa były te, w których wykorzystywano szczepionkę drożdżową.
Purification and partial characterization of aminopeptidase from barley (Hordeum vulgare L.) seeds.
2013
Aminopeptidases (EC 3.4.11) are proteolytic enzymes, which hydrolyze one amino acid from N-terminus of peptidic substrates. Inhibitors of plant aminopeptidases can find an application in agriculture as herbicides. Isolation and partial characterization of aminopeptidase from barley (Hordeum vulgare L.) seeds has been described. The enzyme was purified to molecular homogeneity using a six-step purification procedure (precipitation with (NH4)2SO4, followed by chromatography on Sephadex G-25, DEAE-Sepharose, Sephacryl HR 300, Macro-Prep Q and Phenyl-Sepharose HP columns). The enzyme was purified 365-fold with recovery above 18%. The molecular weight of the purified enzyme was determined by SDS…
Synthesis and biological evaluation of novel peptidomimetics as rhodesain inhibitors
2016
Novel rhodesain inhibitors were developed by combining an enantiomerically pure 3-bromoisoxazoline warhead with a 1,4-benzodiazepine scaffold as specific recognition moiety. All compounds were proven to inhibit rhodesain with Ki values in the low-micromolar range. Their activity towards rhodesain was found to be coupled to an in vitro antitrypanosomal activity, with IC50 values ranging from the mid-micromolar to a low-micromolar value for the most active rhodesain inhibitor (R,S,S)-3. All compounds showed a good selectivity against the target enzyme since all of them were proven to be poor inhibitors of human cathepsin L. Novel rhodesain inhibitors were developed by combining an enantiomeri…
Discovery of a new class of sortase a transpeptidase inhibitors to tackle gram-positive pathogens: 2-(2-phenylhydrazinylidene)alkanoic acids and rela…
2016
A FRET-based random screening assay was used to generate hit compounds as sortase A inhibitors that allowed us to identify ethyl 3-oxo-2-(2-phenylhydrazinylidene)butanoate as an example of a new class of sortase A inhibitors. Other analogues were generated by changing the ethoxycarbonyl function for a carboxy, cyano or amide group, or introducing substituents in the phenyl ring of the ester and acid derivatives. The most active derivative found was 3-oxo-2-(2-(3,4dichlorophenyl)hydrazinylidene)butanoic acid (2b), showing an IC50 value of 50 µM. For a preliminary assessment of their antivirulence properties the new derivatives were tested for their antibiofilm activity. The most active compo…
Dipeptidyl Enoates As Potent Rhodesain Inhibitors That Display a Dual Mode of Action
2015
Dipeptidyl enoates were prepared through a high-yielding two-step synthetic route. They have a dipeptidic structure with a 4-oxoenoate moiety as a warhead with multiple reactive sites. Dipeptidyl enoates were screened against rhodesain and human cathepsins B and L, and were found to be potent and selective inhibitors of rhodesain. Among them (S,E)-ethyl 5-((S)-2-{[(benzyloxy)carbonyl]amino}-3-phenylpropanamido)-7-methyl-4-oxooct-2-enoate (6) was the most potent, with an IC50 value of 16.4 nm and kinact/Ki=1.6×106 m−1 s−1 against rhodesain. These dipeptidyl enoates display a reversible mode of inhibition at very low concentrations and an irreversible mode at higher concentrations. Inhibition…
Conformational Dynamics of the Dengue Virus Protease Revealed by Fluorescence Correlation and Single-Molecule FRET Studies.
2021
The dengue virus protease (DENV-PR) represents an attractive target for counteracting DENV infections. It is generally assumed that DENV-PR can exist in an open and a closed conformation and that active site directed ligands stabilize the closed state. While crystal structures of both the open and the closed conformation were successfully resolved, information about the prevalence of these conformations in solution remains elusive. Herein, we address the question of whether there is an equilibrium between different conformations in solution which can be influenced by addition of a competitive inhibitor. To this end, DENV-PR was statistically labeled by two dye molecules constituting a FRET …