Search results for "Sortase"
showing 6 items of 16 documents
Enzymatic activity of circular sortase A under denaturing conditions: An advanced tool for protein ligation
2014
Abstract Staphylococcus aureus sortase A is a transpeptidase that is extensively used in various protein research applications. Sortase A is highly selective and does not require any cofactors for the catalysis of protein ligation and, importantly, can be produced in high yields. However, the primary disadvantage of this transpeptidase is its inability to access the recognition site within the highly structured regions of folded substrates. To overcome this problem, we developed an Escherichia coli expression system that produces milligram quantities of circularly closed sortase A; efficient enzyme cyclization was achieved by Synechocystis sp. PCC6803 intein-mediated post-translational spli…
Novel Sortase A (SrtA) inhibitors interfere with the formation of staphylococcal biofilms
2013
Staphylococcus aureus, due to its wide arsenal of virulence factors, is a very versatile pathogen responsible for a wide variety of infectious diseases. The virulence factors include the cell-wall associated proteins that have a direct role in the first stage of pathogenesis. The Sortase A (SrtA) transpeptidase is responsible for covalent anchoring to the cell wall of various surface proteins and it is considered a good target to design new antivirulence agents. In this study, we report the identification of an inhibitor of SrtA afforded from the random screening of a small molecular library of around 150 synthetic compounds, through a high throughput assay by using the standard Dabcyl-QALP…
Sortase A: An ideal target for anti-virulence drug development
2014
Sortase A is a membrane enzyme responsible for the anchoring of surface-exposed proteins to the cell wall envelope of Gram-positive bacteria. As a well-studied member of the sortase subfamily catalysing the cell wall anchoring of important virulence factors to the surface of staphylococci, enterococci and streptococci, sortase A plays a critical role in Gram-positive bacterial pathogenesis. It is thus considered a promising target for the development of new anti-infective drugs that aim to interfere with important Gram-positive virulence mechanisms, such as adhesion to host tissues, evasion of host defences, and bio fi lm formation. The additional properties of sortase A as an enzyme that i…
Pyrrolomycins as antimicrobial agents. Microwave-assisted organic synthesis and insights into their antimicrobial mechanism of action
2019
Abstract New compounds able to counteract staphylococcal biofilm formation are needed. In this study we investigate the mechanism of action of pyrrolomycins, whose potential as antimicrobial agents has been demonstrated. We performed a new efficient and easy method to use microwave organic synthesis suitable for obtaining pyrrolomycins in good yields and in suitable amount for their in vitro in-depth investigation. We evaluate the inhibitory activity towards Sortase A (SrtA), a transpeptidase responsible for covalent anchoring in Gram-positive peptidoglycan of many surface proteins involved in adhesion and in biofilm formation. All compounds show a good inhibitory activity toward SrtA, havi…
Asymmetric Disulfanylbenzamides as Irreversible and Selective Inhibitors of Staphylococcus aureus Sortase A
2020
Abstract Staphylococcus aureus is one of the most frequent causes of nosocomial and community‐acquired infections, with drug‐resistant strains being responsible for tens of thousands of deaths per year. S. aureus sortase A inhibitors are designed to interfere with virulence determinants. We have identified disulfanylbenzamides as a new class of potent inhibitors against sortase A that act by covalent modification of the active‐site cysteine. A broad series of derivatives were synthesized to derive structure‐activity relationships (SAR). In vitro and in silico methods allowed the experimentally observed binding affinities and selectivities to be rationalized. The most active compounds were f…
A new class of phenylhydrazinylidene derivatives as inhibitors of Staphylococcus aureus biofilm formation
2016
In the struggle against the emergence of the antibiotic resistance, new molecules targeting biofilm formation could be useful as adjuvant of conventional antibiotics. This study focused on a new class of 2-phenylhydrazinylidene derivatives as antivirulence agents. The compound 12e showed interesting activities against biofilm formation of all tested Staphylococcus aureus strains with IC50 ranging from 1.7 to 43 µM; compounds 12f and 13a resulted strong inhibitors of S. aureus ATCC 6538 and ATCC 29213 biofilm formation with IC50 of 0.9 and 0.8 µM, respectively. A preliminary study on the mechanism of action was carried on evaluating the inhibition of sortase A transpeptidase. Compound 12e re…