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1.
mBio ; 15(9): e0057824, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39133006

RESUMEN

Lugdunin is a microbiome-derived antibacterial agent with good activity against Gram-positive pathogens in vitro and in animal models of nose colonization and skin infection. We have previously shown that lugdunin depletes bacterial energy resources by dissipating the membrane potential of Staphylococcus aureus. Here, we explored the mechanism of action of lugdunin in more detail and show that lugdunin quickly depolarizes cytoplasmic membranes of different bacterial species and acidifies the cytoplasm of S. aureus within minutes due to protonophore activity. Varying the salt species and concentrations in buffers revealed that not only protons are transported, and we demonstrate the binding of the monovalent cations K+, Na+, and Li+ to lugdunin. By comparing known ionophores with various ion transport mechanisms, we conclude that the ion selectivity of lugdunin largely resembles that of 15-mer linear peptide gramicidin A. Direct interference with the main bacterial metabolic pathways including DNA, RNA, protein, and cell wall biosyntheses can be excluded. The previously observed synergism of lugdunin with dermcidin-derived peptides such as DCD-1 in killing S. aureus is mechanistically based on potentiated membrane depolarization. We also found that lugdunin was active against certain eukaryotic cells, however strongly depending on the cell line and growth conditions. While adherent lung epithelial cell lines were almost unaffected, more sensitive cells showed dissipation of the mitochondrial membrane potential. Lugdunin seems specifically adapted to its natural environment in the respiratory tract. The ionophore mechanism is refractory to resistance development and benefits from synergy with host-derived antimicrobial peptides. IMPORTANCE: The vast majority of antimicrobial peptides produced by members of the microbiome target the bacterial cell envelope by many different mechanisms. These compounds and their producers have evolved side-by-side with their host and were constantly challenged by the host's immune system. These molecules are optimized to be well tolerated at their physiological site of production, and their modes of action have proven efficient in vivo. Imbalancing the cellular ion homeostasis is a prominent mechanism among antibacterial natural products. For instance, over 120 naturally occurring polyether ionophores are known to date, and antimicrobial peptides with ionophore activity have also been detected in microbiomes. In this study, we elucidated the mechanism underlying the membrane potential-dissipating activity of the thiazolidine-containing cycloheptapeptide lugdunin, the first member of the fibupeptides discovered in a commensal bacterium from the human nose, which is a promising future probiotic candidate that is not prone to resistance development.


Asunto(s)
Antibacterianos , Ionóforos , Microbiota , Staphylococcus aureus , Humanos , Antibacterianos/farmacología , Cationes/farmacología , Cationes/metabolismo , Sinergismo Farmacológico , Ionóforos/farmacología , Lipopéptidos/farmacología , Lipopéptidos/metabolismo , Pruebas de Sensibilidad Microbiana , Microbiota/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/metabolismo
3.
Nat Commun ; 15(1): 3521, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664456

RESUMEN

Recently, a novel cyclo-heptapeptide composed of alternating D,L-amino acids and a unique thiazolidine heterocycle, called lugdunin, was discovered, which is produced by the nasal and skin commensal Staphylococcus lugdunensis. Lugdunin displays potent antimicrobial activity against a broad spectrum of Gram-positive bacteria, including challenging-to-treat methicillin-resistant Staphylococcus aureus (MRSA). Lugdunin specifically inhibits target bacteria by dissipating their membrane potential. However, the precise mode of action of this new class of fibupeptides remains largely elusive. Here, we disclose the mechanism by which lugdunin rapidly destabilizes the bacterial membrane potential using an in vitro approach. The peptide strongly partitions into lipid compositions resembling Gram-positive bacterial membranes but less in those harboring the eukaryotic membrane component cholesterol. Upon insertion, lugdunin forms hydrogen-bonded antiparallel ß-sheets by the formation of peptide nanotubes, as demonstrated by ATR-FTIR spectroscopy and molecular dynamics simulations. These hydrophilic nanotubes filled with a water wire facilitate not only the translocation of protons but also of monovalent cations as demonstrated by voltage-clamp experiments on black lipid membranes. Collectively, our results provide evidence that the natural fibupeptide lugdunin acts as a peptidic channel that is spontaneously formed by an intricate stacking mechanism, leading to the dissipation of a bacterial cell's membrane potential.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Simulación de Dinámica Molecular , Agua/química , Potenciales de la Membrana/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Membrana Celular/química , Antibacterianos/farmacología , Antibacterianos/química , Lípidos de la Membrana/química , Lípidos de la Membrana/metabolismo , Staphylococcus lugdunensis/efectos de los fármacos , Staphylococcus lugdunensis/química , Staphylococcus lugdunensis/metabolismo , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Pruebas de Sensibilidad Microbiana , Nanotubos/química , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología
4.
Angew Chem Int Ed Engl ; 63(3): e202314028, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38029352

RESUMEN

The caseinolytic protease is a highly conserved serine protease, crucial to prokaryotic and eukaryotic protein homeostasis, and a promising antibacterial and anticancer drug target. Herein, we describe the potent cystargolides as the first natural ß-lactone inhibitors of the proteolytic core ClpP. Based on the discovery of two clpP genes next to the cystargolide biosynthetic gene cluster in Kitasatospora cystarginea, we explored ClpP as a potential cystargolide target. We show the inhibition of Staphylococcus aureus ClpP by cystargolide A and B by different biochemical methods in vitro. Synthesis of semisynthetic derivatives and probes with improved cell penetration allowed us to confirm ClpP as a specific target in S. aureus cells and to demonstrate the anti-virulence activity of this natural product class. Crystal structures show cystargolide A covalently bound to all 14 active sites of ClpP from S. aureus, Aquifex aeolicus, and Photorhabdus laumondii, and reveal the molecular mechanism of ClpP inhibition by ß-lactones, the predominant class of ClpP inhibitors.


Asunto(s)
Dipéptidos , Staphylococcus aureus , Staphylococcus aureus/metabolismo , Dominio Catalítico , Dipéptidos/metabolismo , Virulencia , Endopeptidasa Clp/metabolismo
5.
Chemistry ; 30(10): e202303435, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38051282

RESUMEN

Collinolactone A is a microbial specialized metabolite with a unique 6-10-7 tricyclic bislactone skeleton which was isolated from Streptomyces bacteria. The unusual cyclodecatriene motif features dynamic interconversions of two rotamers. Given the biological profiling of collinolactone A as neuroprotective agent, semisynthetic modifications represent an invaluable strategy to enhance its efficacy. Since understanding conformations and reactions of bioactive substances is crucial for rational structure-based design and synthesis of derivatives, we conducted computational studies on conformational behavior as well as experiments on thermal and acid induced rearrangements of the cyclodecatriene. Experimental conformer ratios of collinolactone A and its biosynthetic ketolactone precursor are well reproduced by computations at the PW6B95-D3/def2-QZVPP//r2 SCAN-3c level. Upon heating collinolactone A in anhydrous dioxane at 100 °C, three collinolactone B stereoisomers exhibiting enollactone structures form via Cope rearrangements. Our computations predict the energetic preference for a boat-like transition state in agreement with the stereochemical outcome of the main reaction pathway. Constriction of the ten-membered ring forms collinolactone C with four annulated rings and an exocyclic double bond. Computations and semisynthetic experiments demonstrate strong preference for an acid-catalyzed reaction pathway over an alternative Alder-ene route to collinolactone C with a prohibitive reaction barrier, again in line with stereochemical observations.


Asunto(s)
Antineoplásicos , Lactonas , Conformación Molecular
6.
Nat Microbiol ; 9(1): 200-213, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38110697

RESUMEN

Antagonistic bacterial interactions often rely on antimicrobial bacteriocins, which attack only a narrow range of target bacteria. However, antimicrobials with broader activity may be advantageous. Here we identify an antimicrobial called epifadin, which is produced by nasal Staphylococcus epidermidis IVK83. It has an unprecedented architecture consisting of a non-ribosomally synthesized peptide, a polyketide component and a terminal modified amino acid moiety. Epifadin combines a wide antimicrobial target spectrum with a short life span of only a few hours. It is highly unstable under in vivo-like conditions, potentially as a means to limit collateral damage of bacterial mutualists. However, Staphylococcus aureus is eliminated by epifadin-producing S. epidermidis during co-cultivation in vitro and in vivo, indicating that epifadin-producing commensals could help prevent nasal S. aureus carriage. These insights into a microbiome-derived, previously unknown antimicrobial compound class suggest that limiting the half-life of an antimicrobial may help to balance its beneficial and detrimental activities.


Asunto(s)
Antiinfecciosos , Infecciones Estafilocócicas , Humanos , Staphylococcus aureus , Péptidos Antimicrobianos , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/prevención & control , Infecciones Estafilocócicas/microbiología , Staphylococcus epidermidis/metabolismo
7.
Nat Commun ; 14(1): 7842, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-38030603

RESUMEN

Antibiotics are central to modern medicine, and yet they are mainly the products of intra and inter-kingdom evolutionary warfare. To understand how nature evolves antibiotics around a common mechanism of action, we investigated the origins of an extremely valuable class of compounds, lipid II targeting glycopeptide antibiotics (GPAs, exemplified by teicoplanin and vancomycin), which are used as last resort for the treatment of antibiotic resistant bacterial infections. Using a molecule-centred approach and computational techniques, we first predicted the nonribosomal peptide synthetase assembly line of paleomycin, the ancestral parent of lipid II targeting GPAs. Subsequently, we employed synthetic biology techniques to produce the predicted peptide and validated its antibiotic activity. We revealed the structure of paleomycin, which enabled us to address how nature morphs a peptide antibiotic scaffold through evolution. In doing so, we obtained temporal snapshots of key selection domains in nonribosomal peptide synthesis during the biosynthetic journey from ancestral, teicoplanin-like GPAs to modern GPAs such as vancomycin. Our study demonstrates the synergy of computational techniques and synthetic biology approaches enabling us to journey back in time, trace the temporal evolution of antibiotics, and revive these ancestral molecules. It also reveals the optimisation strategies nature has applied to evolve modern GPAs, laying the foundation for future efforts to engineer this important class of antimicrobial agents.


Asunto(s)
Antibacterianos , Glicopéptidos , Antibacterianos/farmacología , Glicopéptidos/química , Teicoplanina/química , Teicoplanina/farmacología , Vancomicina/farmacología , Péptidos
8.
Microbiol Spectr ; 11(1): e0317622, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36472430

RESUMEN

Biosynthetic gene clusters (BGCs) encoding the production of bacteriocins are widespread among bacterial isolates and are important genetic determinants of competitive fitness within a given habitat. Staphylococci produce a tremendous diversity of compounds, and the corresponding BGCs are frequently associated with mobile genetic elements, suggesting gain and loss of biosynthetic capacity. Pharmaceutical biology has shown that compound production in heterologous hosts is often challenging, and many BGC recipients initially produce small amounts of compound or show reduced growth rates. To assess whether transfer of BGCs between closely related Staphylococcus aureus strains can be instantly effective or requires elaborate metabolic adaptation, we investigated the intraspecies transfer of a BGC encoding the ribosomally synthesized and posttranslationally modified peptide (RiPP) micrococcin P1 (MP1). We found that acquisition of the BGC by S. aureus RN4220 enabled immediate MP1 production but also imposed a metabolic burden, which was relieved after prolonged cultivation by adaptive mutation. We used a multiomics approach to study this phenomenon and found adaptive evolution to select for strains with increased activity of the tricarboxylic acid cycle (TCA), which enhanced metabolic fitness and levels of compound production. Metabolome analysis revealed increases of central metabolites, including citrate and α-ketoglutarate in the adapted strain, suggesting metabolic adaptation to overcome the BGC-associated growth defects. Our results indicate that BGC acquisition requires genetic and metabolic predispositions, allowing the integration of bacteriocin production into the cellular metabolism. Inappropriate metabolic characteristics of recipients can entail physiological burdens, negatively impacting the competitive fitness of recipients within natural bacterial communities. IMPORTANCE Human microbiomes are critically associated with human health and disease. Importantly, pathogenic bacteria can hide in human-associated communities and can cause disease when the composition of the community becomes unbalanced. Bacteriocin-producing commensals are able to displace pathogens from microbial communities, suggesting that their targeted introduction into human microbiomes might prevent pathogen colonization and infection. However, to develop probiotic approaches, strains are needed that produce high levels of bioactive compounds and retain cellular fitness within mixed bacterial communities. Our work offers insights into the metabolic burdens associated with the production of the bacteriocin micrococcin P1 and highlights evolutionary strategies that increase cellular fitness in the context of production. Metabolic adaptations are most likely broadly relevant for bacteriocin producers and need to be considered for the future development of effective microbiome editing strategies.


Asunto(s)
Bacteriocinas , Staphylococcus aureus , Humanos , Staphylococcus aureus/genética , Bacteriocinas/genética , Bacteriocinas/metabolismo , Bacterias/genética , Staphylococcus/genética , Familia de Multigenes
9.
Microbiol Resour Announc ; 11(8): e0022022, 2022 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-35894627

RESUMEN

The actinomycete Streptomyces sp. strain Gö40/10 has the potential to produce a range of secondary metabolites, one of which is collinolactone, a compound with neuroprotective properties and potential for pharmaceutical applications. The genome was sequenced with Oxford Nanopore Technologies MinION and Illumina MiSeq systems and consists of a single 9,635,564-nucleotide linear chromosome.

10.
Chembiochem ; 23(13): e202200241, 2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35508894

RESUMEN

The design of distinctive chemical synthesis strategies aims for the most efficient routes towards versatile compounds in drug target studies. Here, we establish a powerful hybrid synthetic approach of total chemical and chemoenzymatic synthesis to efficiently obtain various 7-deoxy-sedoheptulose (7dSh, 1) analogues, unique C7 sugars, for structure-activity relationship studies. 7dSh (1) is a rare microbial sugar with in planta herbicidal activity. As natural antimetabolite of 3-dehydroquinate synthase (DHQS), 7dSh (1) inhibits the shikimate pathway, which is essential for the synthesis of aromatic amino acids in bacteria, fungi, and plants, but absent in mammals. As glyphosate, the most used chemical herbicide faces restrictions worldwide, DHQS has gained more attention as valid target of herbicides and antimicrobial agents. In vitro and in vivo analyses of the C7 -deoxysugars confirm DHQS as enzymatic target, highlight the crucial role of uptake for inhibition and add molecular aspects to target mechanism studies of C7 -sugars as our contribution to global efforts for alternative weed-control strategies.


Asunto(s)
Herbicidas , Azúcares , Animales , Herbicidas/farmacología , Mamíferos , Relación Estructura-Actividad
11.
Angew Chem Int Ed Engl ; 60(43): 23212-23216, 2021 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-34415670

RESUMEN

Recently described rhizolutin and collinolactone isolated from Streptomyces Gö 40/10 share the same novel carbon scaffold. Analyses by NMR and X-Ray crystallography verify the structure of collinolactone and propose a revision of rhizolutin's stereochemistry. Isotope-labeled precursor feeding shows that collinolactone is biosynthesized via type I polyketide synthase with Baeyer-Villiger oxidation. CRISPR-based genetic strategies led to the identification of the biosynthetic gene cluster and a high-production strain. Chemical semisyntheses yielded collinolactone analogues with inhibitory effects on L929 cell line. Fluorescence microscopy revealed that only particular analogues induce monopolar spindles impairing cell division in mitosis. Inspired by the Alzheimer-protective activity of rhizolutin, we investigated the neuroprotective effects of collinolactone and its analogues on glutamate-sensitive cells (HT22) and indeed, natural collinolactone displays distinct neuroprotection from intracellular oxidative stress.


Asunto(s)
Diterpenos/farmacología , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/efectos de los fármacos , Animales , Línea Celular , Diterpenos/química , Diterpenos/metabolismo , Ratones , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/metabolismo , Potoroidae , Huso Acromático/efectos de los fármacos
12.
J Biol Chem ; 296: 100621, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33811856

RESUMEN

5-Deoxyadenosine (5dAdo) is the byproduct of many radical S-adenosyl-l-methionine enzyme reactions in all domains of life. 5dAdo is also an inhibitor of the radical S-adenosyl-l-methionine enzymes themselves, making it necessary for cells to construct pathways to recycle or dispose of this toxic metabolite. However, the specific pathways involved have long remained unexplored. Recent research demonstrated a growth advantage in certain organisms by using 5dAdo or intermediates as a sole carbon source and elucidated the corresponding salvage pathway. We now provide evidence using supernatant analysis by GC-MS for another 5dAdo recycling route. Specifically, in the unicellular cyanobacterium Synechococcus elongatus PCC 7942 (S. elongatus), the activity of promiscuous enzymes leads to the synthesis and excretion first of 5-deoxyribose and subsequently of 7-deoxysedoheptulose. 7-Deoxysedoheptulose is an unusual deoxy-sugar, which acts as an antimetabolite of the shikimate pathway, thereby exhibiting antimicrobial and herbicidal activity. This strategy enables organisms with small genomes and lacking canonical gene clusters for the synthesis of secondary metabolites, like S. elongatus, to produce antimicrobial compounds from primary metabolism and enzymatic promiscuity. Our findings challenge the view of bioactive molecules as sole products of secondary metabolite gene clusters and expand the range of compounds that microorganisms can deploy to compete for their ecological niche.


Asunto(s)
Proteínas Bacterianas/metabolismo , Desoxiadenosinas/metabolismo , Hidrolasas/metabolismo , S-Adenosilmetionina/metabolismo , Metabolismo Secundario , Synechococcus/metabolismo , Proteínas Bacterianas/genética , Hidrolasas/genética , Synechococcus/crecimiento & desarrollo
13.
J Med Chem ; 64(7): 4034-4058, 2021 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-33779184

RESUMEN

A new solid-phase peptide synthesis and bioprofiling of the antimicrobial activity of lugdunin, a fibupeptide, enable a comprehensive structure-activity relationship (SAR) study (MRSA Staphylococcus aureus). Distinct lugdunin analogues with variation of the three important amino acids Val2, Trp3, and Leu4 are readily available based on the established high-output synthesis. This efficient synthesis concept takes advantage of the presynthesized thiazolidine building block. To gain further knowledge of SAR, d-Val2, and d-Leu4 were replaced with aliphatic amino acids. For l-Trp3 derivatization, a set of non-natural aromatic amino acids with manifold substitution and annulation patterns precisely shows structural imperatives, starting from the exchange of d-Val6 → d-Trp6 with a 2-fold improved biological activity. d-Trp6-lugdunin analogues with additional variation of d-Val2 and d-Leu4 residues were designed and synthesized followed by antimicrobial profiling. For the first time, these SAR studies deliver valuable information on the tolerance of other amino acids to d-Val2, l-Trp3, and d-Leu4 in the sequence of lugdunin.


Asunto(s)
Antibacterianos/farmacología , Péptidos Cíclicos/farmacología , Tiazolidinas/farmacología , Antibacterianos/síntesis química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Péptidos Cíclicos/síntesis química , Relación Estructura-Actividad , Tiazolidinas/síntesis química
14.
Cell Chem Biol ; 28(8): 1242-1252.e4, 2021 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-33761329

RESUMEN

A big challenge in natural product research of today is rapid dereplication of already known substances, to free capacities for the exploration of new agents. Prompt information on bioactivities and mode of action (MOA) speeds up the lead discovery process and is required for rational compound optimization. Here, we present a bioreporter approach as a versatile strategy for combined bioactivity- and MOA-informed primary screening for antimicrobials. The approach is suitable for directly probing producer strains grown on agar, without need for initial compound enrichment or purification, and works along the entire purification pipeline with culture supernatants, extracts, fractions, and pure substances. The technology allows for MOA-informed purification to selectively prioritize activities of interest. In combination with high-resolution mass spectrometry, the biosensor panel is an efficient and sensitive tool for compound deconvolution. Concomitant information on the affected metabolic pathway enables the selection of appropriate follow-up assays to elucidate the molecular target.


Asunto(s)
Antibacterianos/biosíntesis , Productos Biológicos/metabolismo , Técnicas Biosensibles , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Productos Biológicos/aislamiento & purificación , Descubrimiento de Drogas , Escherichia coli/efectos de los fármacos , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana
15.
Artículo en Inglés | MEDLINE | ID: mdl-33106269

RESUMEN

Lugdunin is the first reported nonribosomally synthesized antibiotic from human microbiomes. Its production by the commensal Staphylococcus lugdunensis eliminates the pathogen Staphylococcus aureus from human nasal microbiomes. The cycloheptapeptide lugdunin is the founding member of the new class of fibupeptide antibiotics, which have a novel mode of action and represent promising new antimicrobial agents. How S. lugdunensis releases and achieves producer self-resistance to lugdunin has remained unknown. We report that two ABC transporters encoded upstream of the lugdunin-biosynthetic operon have distinct yet overlapping roles in lugdunin secretion and self-resistance. While deletion of the lugEF transporter genes abrogated most of the lugdunin secretion, the lugGH transporter genes had a dominant role in resistance. Yet all four genes were required for full-level lugdunin resistance. The small accessory putative membrane protein LugI further contributed to lugdunin release and resistance levels conferred by the ABC transporters. Whereas LugIEFGH also conferred resistance to lugdunin congeners with inverse structures or with amino acid exchange at position 6, they neither affected the susceptibility to a lugdunin variant with an exchange at position 2 nor to other cyclic peptide antimicrobials such as daptomycin or gramicidin S. The obvious selectivity of the resistance mechanism raises hopes that it will not confer cross-resistance to other antimicrobials or to optimized lugdunin derivatives to be used for the prevention and treatment of S. aureus infections.


Asunto(s)
Antiinfecciosos , Infecciones Estafilocócicas , Staphylococcus lugdunensis , Transportadoras de Casetes de Unión a ATP/genética , Antibacterianos/farmacología , Humanos , Pruebas de Sensibilidad Microbiana , Péptidos Cíclicos/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus , Tiazolidinas
16.
Nat Commun ; 10(1): 2730, 2019 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-31227691

RESUMEN

Recently our groups discovered lugdunin, a new cyclic peptide antibiotic that inhibits Staphylococcus aureus epithelial colonization in humans and rodents. In this work, we analyzed its immuno-modulatory and antimicrobial potential as a single agent or in combination with other microbiota- or host-derived factors. We show that pretreatment of primary human keratinocytes or mouse skin with lugdunin in combination with microbiota-derived factors results in a significant reduction of S. aureus colonization. Moreover, lugdunin increases expression and release of LL-37 and CXCL8/MIP-2 in human keratinocytes and mouse skin, and results in the recruitment of monocytes and neutrophils in vivo, both by a TLR/MyD88-dependent mechanism. Interestingly, S. aureus elimination by lugdunin is additionally achieved by synergistic antimicrobial activity with LL-37 and dermcidin-derived peptides. In summary, our results indicate that lugdunin provides multi-level protection against S. aureus and may thus become a promising treatment option for S. aureus skin infections in the future.


Asunto(s)
Antibacterianos/farmacología , Inmunidad Innata/efectos de los fármacos , Péptidos Cíclicos/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Tiazolidinas/farmacología , Animales , Antibacterianos/uso terapéutico , Péptidos Catiónicos Antimicrobianos/inmunología , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Humanos , Queratinocitos/efectos de los fármacos , Queratinocitos/inmunología , Queratinocitos/microbiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microbiota/efectos de los fármacos , Microbiota/inmunología , Péptidos/inmunología , Péptidos Cíclicos/uso terapéutico , Cultivo Primario de Células , Piel/efectos de los fármacos , Piel/inmunología , Piel/microbiología , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/microbiología , Tiazolidinas/uso terapéutico , Catelicidinas
17.
Int J Med Microbiol ; 309(5): 319-324, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31138496

RESUMEN

Cell wall biosynthesis represents a valid target for antibacterial action but only a limited number of chemical structure classes selectively interact with specific enzymes or protein structures like transporters of the cell envelope. The integral membrane protein MraY translocase is essential for peptidoglycan biosynthesis catalysing the transfer of the peptidoglycan precursor phospho-MurNAc-pentapeptide to the lipid carrier undecaprenyl phosphate, thereby generating the cell wall intermediate lipid I. Not present in eukaryotic cells, MraY is a member of the superfamily of yet not well-understood integral membrane enzymes which involve proteins for bacterial lipopolysaccharide and teichoic acid or eukaryotic N-linked saccharides biosynthesis. Different natural nucleoside antibiotics as inhibitors of MraY translocase have been discovered comprising a glycosylated heterocyclic pyrimidin base among other potential lipid-, peptidic- or sugar moieties. Caprazamycins are liponucleoside antibiotics isolated from Streptomyces sp. MK730-62F2. They possess activity in vitro against Gram-positive bacteria, in particular against the genus Mycobacterium including M. intracellulare, M. avium and M. tuberculosis. Structural elucidation revealed the (+)-caprazol core skeleton as a unique moiety, the caprazamycins share with other MraY inhibitors such as the liposidomycins, A-90289 and the muraminomicins. They also share structural features such as uridyl-, aminoribosyl- and fatty acyl-moieties with other MraY translocase inhibitors like FR-900493 and the muraymycins. Intensive studies on their biosynthesis during the last decade identified not only common initial biosynthetic steps, but also revealed possible branching points towards individual biosynthesis of the respective compound. Structural diversity of caprazamycins was generated by feeding experiments, genetic engineering of the biosynthetic gene clusters and chemical synthesis for structure activity relationship studies with its target, MraY translocase.


Asunto(s)
Antibacterianos/química , Azepinas/química , Proteínas Bacterianas/antagonistas & inhibidores , Nucleósidos/química , Streptomyces/química , Transferasas/antagonistas & inhibidores , Antibacterianos/farmacología , Vías Biosintéticas , Estructura Molecular , Familia de Multigenes , Mycobacterium/efectos de los fármacos , Relación Estructura-Actividad , Transferasas (Grupos de Otros Fosfatos Sustitutos)
18.
Angew Chem Int Ed Engl ; 58(27): 9234-9238, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31059155

RESUMEN

Lugdunin, a novel thiazolidine cyclopeptide, exhibits micromolar activity against methicillin-resistant Staphylococcus aureus (MRSA). For structure-activity relationship (SAR) studies, synthetic analogues obtained from alanine and stereo scanning as well as peptides with modified thiazolidine rings were tested for antimicrobial activity. The thiazolidine ring and the alternating d- and l-amino acid backbone are essential. Notably, the non-natural enantiomer displays equal activity, thus indicating the absence of a chiral target. The antibacterial activity strongly correlates with dissipation of the membrane potential in S. aureus. Lugdunin equalizes pH gradients in artificial membrane vesicles, thereby maintaining membrane integrity, which demonstrates that proton translocation is the mode of action (MoA). The incorporation of extra tryptophan or propargyl moieties further expands the diversity of this class of thiazolidine cyclopeptides.


Asunto(s)
Antiinfecciosos/síntesis química , Péptidos Cíclicos/química , Tiazolidinas/química , Alanina/química , Secuencia de Aminoácidos , Antiinfecciosos/química , Antiinfecciosos/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Péptidos Cíclicos/síntesis química , Péptidos Cíclicos/farmacología , Protones , Estereoisomerismo , Relación Estructura-Actividad , Tiazolidinas/síntesis química , Tiazolidinas/farmacología
19.
Nat Commun ; 10(1): 545, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30710081

RESUMEN

Antimetabolites are small molecules that inhibit enzymes by mimicking physiological substrates. We report the discovery and structural elucidation of the antimetabolite 7-deoxy-sedoheptulose (7dSh). This unusual sugar inhibits the growth of various prototrophic organisms, including species of cyanobacteria, Saccharomyces, and Arabidopsis. We isolate bioactive 7dSh from culture supernatants of the cyanobacterium Synechococcus elongatus. A chemoenzymatic synthesis of 7dSh using S. elongatus transketolase as catalyst and 5-deoxy-D-ribose as substrate allows antimicrobial and herbicidal bioprofiling. Organisms treated with 7dSh accumulate 3-deoxy-D-arabino-heptulosonate 7-phosphate, which indicates that the molecular target is 3-dehydroquinate synthase, a key enzyme of the shikimate pathway, which is absent in humans and animals. The herbicidal activity of 7dSh is in the low micromolar range. No cytotoxic effects on mammalian cells have been observed. We propose that the in vivo inhibition of the shikimate pathway makes 7dSh a natural antimicrobial and herbicidal agent.


Asunto(s)
Anabaena/crecimiento & desarrollo , Antimetabolitos/farmacología , Arabidopsis/crecimiento & desarrollo , Cianobacterias/metabolismo , Heptosas/farmacología , Redes y Vías Metabólicas , Ácido Shikímico/metabolismo , Anabaena/efectos de los fármacos , Antifúngicos/farmacología , Arabidopsis/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Línea Celular , Heptosas/aislamiento & purificación , Herbicidas/toxicidad , Redes y Vías Metabólicas/efectos de los fármacos , Metaboloma , Liasas de Fósforo-Oxígeno/antagonistas & inhibidores , Liasas de Fósforo-Oxígeno/metabolismo , Fotosíntesis/efectos de los fármacos , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Synechococcus/metabolismo
20.
Antibiotics (Basel) ; 7(3)2018 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-29958422

RESUMEN

The structural repertoire of bioactive naphthacene quinones is expanded by engineering Streptomyces albus to express the lysolipin minimal polyketide synthase II (PKS II) genes from Streptomyces tendae Tü 4042 (llpD-F) with the corresponding cyclase genes llpCI-CIII. Fermentation of the recombinant strain revealed the two new polyaromatic tridecaketides lysoquinone-TH1 (7, identified) and TH2 (8, postulated structure) as engineered congeners of the dodecaketide lysolipin (1). The chemical structure of 7, a benzo[a]naphthacene-8,13-dione, was elucidated by NMR and HR-MS and confirmed by feeding experiments with [1,2-13C2]-labeled acetate. Lysoquinone-TH1 (7) is a pentangular polyphenol and one example of such rare extended polyaromatic systems of the benz[a]napthacene quinone type produced by the expression of a minimal PKS II in combination with cyclases in an artificial system. While the natural product lysolipin (1) has antimicrobial activity in nM-range, lysoquinone-TH1 (7) showed only minor potency as inhibitor of Gram-positive microorganisms. The bioactivity profiling of lysoquinone-TH1 (7) revealed inhibitory activity towards phosphodiesterase 4 (PDE4), an important target for the treatment in human health like asthma or chronic obstructive pulmonary disease (COPD). These results underline the availability of pentangular polyphenolic structural skeletons from biosynthetic engineering in the search of new chemical entities in drug discovery.

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