Molecular sieves are highly active and selective catalysts with industrial potential for acylation reactions. Zeolites are the catalysts of choice when shape selectivity influences the preferential formation of some products, while high conversions are achieved over mesoporous catalysts with enhanced diffusion rates of reactants and products. In this Minireview, we focus on the understanding of the relationship among the structure of molecular sieve, type and concentration of acid sites and activity/selectivity in various acylations of aromatic and olefinic hydrocarbons. The products of these acylation reactions are important compounds for the pharmaceutical industry, fragrance and flavor materials, dyes, polymers, agrochemicals, and other applications.

• MeSH
• acylace * MeSH
• katalýza * MeSH
• pojmy organické chemie MeSH
• silikáty MeSH
• sloučeniny vápníku MeSH
• technologie zelené chemie metody   MeSH
• zeolity MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• calcium silicate MeSH Prohlížeč
• silikáty MeSH
• sloučeniny vápníku MeSH
• zeolity MeSH

The cyclin-dependent kinase inhibitor, CAN508, was protected with di-tert-butyl dicarbonate to access the amino-benzoylated pyrazoles. The bromo derivatives were further arylated by Suzuki-Miyaura coupling using the XPhos Pd G2 pre-catalyst. The coupling reaction provided generally the para-substituted benzoylpyrazoles in the higher yields than the meta-substituted ones. The Boc groups were only utilized as directing functionalities for the benzoylation step and were hydrolyzed under conditions of Suzuki-Miyaura coupling, which allowed for elimination of the additional deprotection step.

• Klíčová slova
• Boc-protection, CDK inhibitor, Suzuki-Miyaura reaction, XPhos Pd G2, acylation, pyrazole,
• MeSH
• acylace MeSH
• azosloučeniny chemie   MeSH
• hydrolýza MeSH
• inhibitory proteinkinas chemie   MeSH
• katalýza MeSH
• molekulární struktura MeSH
• palladium chemie   MeSH
• pyrazoly chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• azosloučeniny MeSH
• CAN 508 MeSH Prohlížeč
• inhibitory proteinkinas MeSH
• palladium MeSH
• pyrazoly MeSH

The Bordetella pertussis RTX (repeat in toxin family protein) adenylate cyclase toxin-hemolysin (ACT) acquires biological activity upon a single amide-linked palmitoylation of the epsilon-amino group of lysine 983 (Lys983) by the accessory fatty-acyltransferase CyaC. However, an additional conserved RTX acylation site can be identified in ACT at lysine 860 (Lys860), and this residue becomes palmitoylated when recombinant ACT (r-Ec-ACT) is produced together with CyaC in Escherichia coli K12. We have eliminated this additional acylation site by replacing Lys860 of ACT with arginine, leucine, and cysteine residues. Two-dimensional gel electrophoresis and microcapillary high performance liquid chromatography/tandem mass spectrometric analyses of mutant proteins confirmed that the two sites are acylated independently in vivo and that mutations of Lys860 did not affect the quantitative acylation of Lys983 by palmitoyl (C16:0) and palmitoleil (cis Delta9 C16:1) fatty-acyl groups. Nevertheless, even the most conservative substitution of lysine 860 by an arginine residue caused a 10-fold decrease of toxin activity. This resulted from a 5-fold reduction of cell association capacity and a further 2-fold reduction in cell penetration efficiency of the membrane-bound K860R toxin. These results suggest that lysine 860 plays by itself a crucial structural role in membrane insertion and translocation of the toxin, independently of its acylation status.

• MeSH
• acylace MeSH
• adenylátcyklasový toxin MeSH
• adenylátcyklasy chemie   metabolismus   MeSH
• bakteriální proteiny chemie   genetika   metabolismus   MeSH
• Bordetella pertussis enzymologie   MeSH
• DNA primery MeSH
• faktory virulence rodu Bordetella chemie   genetika   metabolismus   MeSH
• konzervovaná sekvence MeSH
• lysin chemie   metabolismus   MeSH
• mastné kyseliny metabolismus   MeSH
• mutageneze cílená MeSH
• proteinové prekurzory chemie   genetika   metabolismus   MeSH
• sekvence nukleotidů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• adenylátcyklasy MeSH
• bakteriální proteiny MeSH
• DNA primery MeSH
• faktory virulence rodu Bordetella MeSH
• lysin MeSH
• mastné kyseliny MeSH
• proteinové prekurzory MeSH

In a wide range of organisms, from bacteria to humans, numerous proteins have to be posttranslationally acylated to become biologically active. Bacterial repeats in toxin (RTX) cytolysins form a prominent group of proteins that are synthesized as inactive protoxins and undergo posttranslational acylation on ε-amino groups of two internal conserved lysine residues by co-expressed toxin-activating acyltransferases. Here, we investigated how the chemical nature, position, and number of bound acyl chains govern the activities of Bordetella pertussis adenylate cyclase toxin (CyaA), Escherichia coli α-hemolysin (HlyA), and Kingella kingae cytotoxin (RtxA). We found that the three protoxins are acylated in the same E. coli cell background by each of the CyaC, HlyC, and RtxC acyltransferases. We also noted that the acyltransferase selects from the bacterial pool of acyl-acyl carrier proteins (ACPs) an acyl chain of a specific length for covalent linkage to the protoxin. The acyltransferase also selects whether both or only one of two conserved lysine residues of the protoxin will be posttranslationally acylated. Functional assays revealed that RtxA has to be modified by 14-carbon fatty acyl chains to be biologically active, that HlyA remains active also when modified by 16-carbon acyl chains, and that CyaA is activated exclusively by 16-carbon acyl chains. These results suggest that the RTX toxin molecules are structurally adapted to the length of the acyl chains used for modification of their acylated lysine residue in the second, more conserved acylation site.

• Klíčová slova
• RTX toxin, acylation, acyltransferase, adenylate cyclase toxin (CyaA), bacterial toxin, cytotoxicity, cytotoxin (RtxA), fatty acid, fatty acyl, posttranslational modification, protein acylation, protein translocation, protoxin, α-hemolysin (HlyA),
• MeSH
• acyltransferasy metabolismus   MeSH
• Bacteria metabolismus   MeSH
• bakteriální proteiny metabolismus   MeSH
• buněčné linie MeSH
• hemolyziny metabolismus   MeSH
• mastné kyseliny metabolismus   MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acyltransferasy MeSH
• bakteriální proteiny MeSH
• hemolyziny MeSH
• mastné kyseliny MeSH

The capacity of adenylate cyclase toxin (ACT) to penetrate into target cells depends on post-translational fatty-acylation by the acyltransferase CyaC, which can palmitoylate the conserved lysines 983 and 860 of ACT. Here, the in vivo acylating capacity of a set of mutated CyaC acyltransferases was characterized by two-dimensional gel electrophoresis and mass spectrometric analyses of the ACT product. Substitutions of the potentially catalytic serine 20 and histidine 33 residues ablated acylating activity of CyaC. Conservative replacements of alanine 140 by glycine (A140G) and valine (A140V) residues, however, affected selectivity of CyaC for the two acylation sites on ACT. Activation by the A140G variant of CyaC generated a mixture of bi- and monoacylated ACT molecules, modified either at both Lys-860 and Lys-983, or only at Lys-860, respectively. In contrast, the A140V CyaC produced a nearly 1:1 mixture of nonacylated pro-ACT with ACT monoacylated almost exclusively at Lys-983. The respective proportion of toxin molecules acylated at Lys-983 correlated well with the cell-invasive activity of both ACT mixtures, which was about half of that of ACT fully acylated on Lys-983 by intact CyaC. These results show that acylation of Lys-860 alone does not confer cell-invasive activity on ACT, whereas acylation of Lys-983 is necessary and sufficient.

• MeSH
• 2D gelová elektroforéza MeSH
• acylace MeSH
• acyltransferasy chemie   genetika   metabolismus   MeSH
• adenylátcyklasový toxin * MeSH
• Bordetella pertussis enzymologie   MeSH
• erytrocyty účinky léků   metabolismus   patologie   MeSH
• faktory virulence rodu Bordetella chemie   genetika   metabolismus   toxicita   MeSH
• hemolýza účinky léků   MeSH
• histidin genetika   metabolismus   MeSH
• hmotnostní spektrometrie MeSH
• kyselina palmitová metabolismus   MeSH
• lysin genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• mutace MeSH
• ovce MeSH
• peptidové fragmenty chemie   metabolismus   MeSH
• posttranslační úpravy proteinů * MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• serin genetika   metabolismus   MeSH
• substituce aminokyselin MeSH
• substrátová specifita MeSH
• vazebná místa MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• Názvy látek
• acyltransferasy MeSH
• adenylátcyklasový toxin * MeSH
• faktory virulence rodu Bordetella MeSH
• histidin MeSH
• kyselina palmitová MeSH
• lysin MeSH
• peptidové fragmenty MeSH
• serin MeSH

The Bordetella adenylate cyclase toxin-hemolysin (CyaA, ACT, or AC-Hly) forms cation-selective membrane channels and delivers into the cytosol of target cells an adenylate cyclase domain (AC) that catalyzes uncontrolled conversion of cellular ATP to cAMP. Both toxin activities were previously shown to depend on post-translational activation of proCyaA to CyaA by covalent palmitoylation of the internal Lys983 residue (K983). CyaA, however, harbors a second RTX acylation site at residue Lys860 (K860), and the role of K860 acylation in toxin activity is unclear. We produced in E. coli the CyaA-K860R and CyaA-K983R toxin variants having the Lys860 and Lys983 acylation sites individually ablated by arginine substitutions. When examined for capacity to form membrane channels and to penetrate sheep erythrocytes, the CyaA-K860R acylated on Lys983 was about 1 order of magnitude more active than CyaA-K983R acylated on Lys860, although, in comparison to intact CyaA, both monoacylated constructs exhibited markedly reduced activities in erythrocytes. Channels formed in lipid bilayers by CyaA-K983R were importantly less selective for cations than channels formed by CyaA-K860R, intact CyaA, or proCyaA, showing that, independent of its acylation status, the Lys983 residue may play a role in toxin structures that determine the distribution of charged residues at the entry or inside of the CyaA channel. While necessary for activity on erythrocytes, acylation of Lys983 was also sufficient for the full activity of CyaA on CD11b+ J774A.1 monocytes. In turn, acylation of Lys860 alone did not permit toxin activity on erythrocytes, while it fully supported the high-affinity binding of CyaA-K983R to the toxin receptor CD11b/CD18 and conferred on CyaA-K983R a reduced but substantial capacity to penetrate and kill the CD11b+ cells. This is the first evidence that acylation of Lys860 may play a role in the biological activity of CyaA, even if redundant to the acylation of Lys983.

• MeSH
• acylace MeSH
• adenylátcyklasový toxin chemie   toxicita   MeSH
• antigeny CD11b metabolismus   MeSH
• buněčné linie MeSH
• erytrocyty účinky léků   MeSH
• iontové kanály chemie   metabolismus   MeSH
• kationty MeSH
• kompetitivní vazba MeSH
• křečci praví MeSH
• lysin chemie   MeSH
• makrofágy účinky léků   MeSH
• myši MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• antigeny CD11b MeSH
• iontové kanály MeSH
• kationty MeSH
• lysin MeSH

Fully acetylated deoxyfluorinated hexosamine analogues and non-fluorinated 3,4,6-tri-O-acylated N-acetyl-hexosamine hemiacetals have previously been shown to display moderate anti-proliferative activity. We prepared a set of deoxyfluorinated GlcNAc and GalNAc hemiacetals that comprised both features: O-acylation at the non-anomeric positions with an acetyl, propionyl and butanoyl group, and deoxyfluorination at selected positions. Determination of the in vitro cytotoxicity towards the MDA-MB-231 breast cancer and HEK-293 cell lines showed that deoxyfluorination enhanced cytotoxicity in most analogues. Increasing the ester alkyl chain length had a variable effect on the cytotoxicity of fluoro analogues, which contrasted with non-fluorinated hemiacetals where butanoyl derivatives had always higher cytotoxicity than acetates. Reaction with 2-phenylethanethiol indicated that the recently described S-glyco-modification is an unlikely cause of cytotoxicity.

• MeSH
• acetaly chemie   farmakologie   chemická syntéza   MeSH
• acetylgalaktosamin chemie   farmakologie   MeSH
• acetylglukosamin chemie   farmakologie   MeSH
• acylace MeSH
• antitumorózní látky farmakologie   chemie   chemická syntéza   MeSH
• galaktosamin chemie   farmakologie   MeSH
• halogenace * MeSH
• HEK293 buňky MeSH
• lidé MeSH
• molekulární struktura MeSH
• nádorové buněčné linie MeSH
• proliferace buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetaly MeSH
• acetylgalaktosamin MeSH
• acetylglukosamin MeSH
• antitumorózní látky MeSH
• galaktosamin MeSH

Kingella kingae is a member of the commensal oropharyngeal flora of young children. Improvements in detection methods have led to the recognition of K. kingae as an emerging pathogen that frequently causes osteoarticular infections in children and a severe form of infective endocarditis in children and adults. Kingella kingae secretes a membrane-damaging RTX (Repeat in ToXin) toxin, RtxA, which is implicated in the development of clinical infections. However, the mechanism by which RtxA recognizes and kills host cells is largely unexplored. To facilitate structure-function studies of RtxA, we have developed a procedure for the overproduction and purification of milligram amounts of biologically active recombinant RtxA. Mass spectrometry analysis revealed the activation of RtxA by post-translational fatty acyl modification on the lysine residues 558 and/or 689 by the fatty-acyltransferase RtxC. Acylated RtxA was toxic to various human cells in a calcium-dependent manner and possessed pore-forming activity in planar lipid bilayers. Using various biochemical and biophysical approaches, we demonstrated that cholesterol facilitates the interaction of RtxA with artificial and cell membranes. The results of analyses using RtxA mutant variants suggested that the interaction between the toxin and cholesterol occurs via two cholesterol recognition/interaction amino acid consensus motifs located in the C-terminal portion of the pore-forming domain of the toxin. Based on our observations, we conclude that the cytotoxic activity of RtxA depends on post-translational acylation of the K558 and/or K689 residues and on the toxin binding to cholesterol in the membrane.

• MeSH
• acylace MeSH
• bakteriální toxiny genetika   metabolismus   MeSH
• buněčná membrána metabolismus   MeSH
• buněčné linie MeSH
• cholesterol metabolismus   MeSH
• Kingella kingae enzymologie   genetika   MeSH
• lidé MeSH
• lysin chemie   MeSH
• posttranslační úpravy proteinů * MeSH
• rekombinantní proteiny metabolismus   MeSH
• transaminasy genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální toxiny MeSH
• cholesterol MeSH
• lysin MeSH
• rekombinantní proteiny MeSH
• transaminasy MeSH

This paper describes a unified approach toward diglycosylamines using methanolic ammonia. All the glycosylamines prepared have been fully characterized, and their anomeric configuration has been determined. The article presents a novel method for the N-acylation of diglycosylamines and other electron-poor glycosylamines, which employs nitromethane as a solvent in carboxylic anhydride acylation under acidic conditions. The feasibility of this transformation is represented by a wide range of reaction substrates. All glycosylamides are formed solely with β-configuration. These two reactions constitute a simple and effective route to the synthesis of a novel class of compounds with an N-glycosidic linkage.

• Klíčová slova
• Glycosylamides, Glycosylamines, N-Acylation, N-Glycosylation,
• MeSH
• acylace MeSH
• elektrony * MeSH
• glykosidy * MeSH
• glykosylace MeSH
• rozpouštědla MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• glykosidy * MeSH
• rozpouštědla MeSH

Kingella kingae, an emerging pediatric pathogen, secretes the pore-forming toxin RtxA, which has been implicated in the development of various invasive infections. RtxA is synthesized as a protoxin (proRtxA), which gains its biological activity by fatty acylation of two lysine residues (K558 and K689) by the acyltransferase RtxC. The low acylation level of RtxA at K558 (2-23 %) suggests that the complete acylation at K689 is crucial for toxin activity. Using a bacterial two-hybrid system, we show that substitutions of K558, but not K689, partially reduce the interaction of proRtxA with RtxC and that the acyltransferase interacts independently with each acylated site in vivo. While substitutions of K558 had no effect on the acylation of K689, substitutions of K689 resulted in an average 40 % increase in the acylation of K558. RtxA mutants monoacylated at either K558 or K689 irreversibly bound to erythrocyte membranes, with binding efficiency corresponding to the extent of lysine acylation. However, these mutants lysed erythrocytes with similarly low efficiency as nonacylated proRtxA and showed only residual overall membrane activity in planar lipid bilayers. Interestingly, despite forming fewer pores, the monoacylated mutants exhibited single-pore characteristics, such as conductance and lifetime, similar to those of intact RtxA. These findings indicate that the acylation at either K558 or K689 is sufficient for the irreversible insertion of RtxA into the membrane, but not for the efficient formation of membrane pores. Alternatively, K558 and K689 per se may play a crucial structural role in pore formation, regardless of their acylation status.

• Klíčová slova
• Acylation, Bacterial two-hybrid system, Kingella kingae, Planar lipid membranes, Pore-forming toxin, RtxA,
• Publikační typ
• časopisecké články MeSH