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1.
J Nat Prod ; 84(1): 46-55, 2021 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-33342211

RESUMEN

Naphthoquinones isolated from Quambalaria cyanescens (quambalarines) are natural pigments possessing significant cytotoxic and antimicrobial properties. Determining the structure of naphthoquinone compounds is important for the understanding of their biological activities and the informed synthesis of related analogues. Identifying quambalarines is challenging, because they contain a hydroxylated naphthoquinone scaffold and have limited solubility. Here, we report a detailed structural study of quambalarine derivatives, which form strong intramolecular hydrogen bonds (IMHBs) that enable the formation of several tautomers; these tautomers may complicate structural investigation due to their fast interconversion. To investigate tautomeric equilibria and identify new quambalarines, we complemented the experimental NMR spectroscopy data with density functional theory (DFT) calculations.


Asunto(s)
Antiinfecciosos/farmacología , Antineoplásicos/farmacología , Basidiomycota/química , Naftoquinonas/farmacología , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Enlace de Hidrógeno , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Estructura Molecular , Naftoquinonas/química , Naftoquinonas/aislamiento & purificación
2.
Mol Phylogenet Evol ; 123: 73-87, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29481949

RESUMEN

The ergot, genus Claviceps, comprises approximately 60 species of specialised ovarial grass parasites famous for the production of food toxins and pharmaceutics. Although the ergot has been known for centuries, its evolution have not been resolved yet. Our approach combining multilocus phylogeny, molecular dating and the study of ecological, morphological and metabolic features shows that Claviceps originated in South America in the Palaeocene on a common ancestor of BEP (subfamilies Bambusoideae, Ehrhartoideae, Pooideae) and PACMAD (subfamilies Panicoideae, Aristidoideae, Chloridoideae, Micrairoideae, Arundinoideae, Danthonioideae) grasses. Four clades described here as sections diverged during the Paleocene and Eocene. Since Claviceps are parasitic fungi with a close relationship with their host plants, their evolution is influenced by interactions with the new hosts, either by the spread to a new continent or the radiation of the host plants. Three of the sections possess very narrow host ranges and biogeographical distributions and have relatively low toxicity. On the contrary, the section Claviceps, comprising the rye ergot, C. purpurea, is unique in all aspects. Fungi in this section of North American origin have spread all over the world and infect grasses in all subfamilies as well as sedges, and it is the only section synthesising toxic ergopeptines and secalonic acids. The evolutionary success of the Claviceps section members can be explained by high toxin presence, serving as feeding deterrents and playing a role in their protective mutualism with host plants. Closely related taxa Neoclaviceps monostipa and Cepsiclava phalaridis were combined into the genus Aciculosporium.


Asunto(s)
Claviceps/clasificación , Filogenia , Teorema de Bayes , Alcaloides de Claviceps/biosíntesis , Alcaloides de Claviceps/química , Sitios Genéticos , Geografía , Especificidad del Huésped , Metabolismo Secundario , América del Sur , Factores de Tiempo
3.
J Nat Prod ; 79(9): 2304-14, 2016 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-27571379

RESUMEN

Quambalarine B (QB) is a secondary metabolite produced by the basidiomycete Quambalaria cyanescens with potential anticancer activity. Here we report that QB at low micromolar concentration inhibits proliferation of several model leukemic cell lines (Jurkat, NALM6, and REH), whereas higher concentrations induce cell death. By contrast, the effect of QB on primary leukocytes (peripheral blood mononuclear cells) is significantly milder with lower toxicity and cytostatic activity. Moreover, QB inhibited expression of the C-MYC oncoprotein and mRNA expression of its target genes, LDHA, PKM2, and GLS. Finally, QB blocked the phosphorylation of P70S6K, a downstream effector kinase in mTOR signaling that regulates translation of C-MYC. This observation could explain the molecular mechanism behind the antiproliferative and cytotoxic effects of QB on leukemic cells. Altogether, our results establish QB as a promising molecule in anticancer treatment.


Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Basidiomycota/química , Naftoquinonas/química , Naftoquinonas/farmacología , Antineoplásicos/sangre , Antineoplásicos/aislamiento & purificación , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Células Jurkat/efectos de los fármacos , Leucocitos Mononucleares/efectos de los fármacos , Estructura Molecular , Naftoquinonas/sangre , Naftoquinonas/síntesis química , Naftoquinonas/aislamiento & purificación , Fosforilación , Proteínas Quinasas S6 Ribosómicas 70-kDa , Transducción de Señal/fisiología , Serina-Treonina Quinasas TOR
4.
J Nat Prod ; 78(8): 2095-103, 2015 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-26273725

RESUMEN

A new, efficient, and general semisynthesis of hydnocarpin-type flavonolignans was developed and optimized, enabling gram-scale production of hydnocarpin D (2). Moreover, the syntheses of optically pure hydnocarpin isomers [(10R,11R)-hydnocarpin (1a), (10R,11R)-hydnocarpin D (2a), and (10S,11S)-hydnocarpin D (2b)], as well as the synthesis of isohydnocarpin (8), were achieved for the first time utilizing this new method. The synthesis is based on the two-step transformation of the readily available flavonolignans from milk thistle (Silybum marianum), accessible by isolation from the commercial extract silymarin. The first step relies on the regioselective formylation of the C-3 hydroxy group of the dihydroflavonol-type precursor using the Vilsmeier-Haack reagent, followed by formic acid elimination by triethylamine in the second step. The synthesized compounds were effective inhibitors of Staphylococcus aureus biofilm formation, with (10S,11S)-hydnocarpin D (2b) being the most potent inhibitor. Furthermore, the effect of glucose on biofilm formation was tested, and glucose decreased the biofilm inhibitory activity of 2b. Moreover, 2b increased the susceptibility of Staph. aureus to enrofloxacin.


Asunto(s)
Biopelículas/efectos de los fármacos , Flavonolignanos/aislamiento & purificación , Flavonolignanos/farmacología , Silybum marianum/química , Staphylococcus aureus/efectos de los fármacos , Antioxidantes , Cromatografía Líquida de Alta Presión , Flavonolignanos/química , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Silimarina/química , Relación Estructura-Actividad
5.
ACS Omega ; 9(31): 33789-33804, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39130536

RESUMEN

This study recognized biologically produced gold nanoparticles (AuNPs) as multiple cargo carriers with a perspective of drug delivery into specialized tumor cells in vivo. Paclitaxel (PTX), transferrin, and antimiR-135b were conjugated with AuNPs and their uptake by mouse tumor cells in an induced breast cancer model was investigated. Each of the above-mentioned molecules was conjugated to the AuNPs separately as well as simultaneously, loading efficiency of each cargo was assessed, and performance of the final product (FP) was judged. After tumor induction in BALB/c mice, sub-IC50 doses of FP as well as control AuNPs, PTX, and phosphate buffered saline were administered in vivo. Round AuNPs were prepared using Fusarium oxysporum and exhibited a size of 13 ± 1.3 nm and a zeta potential of -35.8 ± 1.3 mV. The cytotoxicity of individual conjugates and FP were tested by MTT assay in breast tumor cells 4T1 and nontumor fibroblasts NIH/3T3 cells. The conjugation of individual molecules with AuNPs was confirmed, and FP (size of 54 ± 14 nm and zeta potential of -31.9 ± 2.08 mV) showed higher 4T1-specific toxicity in vitro when compared to control conjugates. After in vivo application of the FP, transmission electron microscopy analyses proved the presence of AuNPs in the tumor cells. Hematoxylin and eosin staining of the tumor tissue revealed that the FP group exhibited the highest amounts of inflammatory, necrotic, and apoptotic cells in contrast to the control groups. Finally, qPCR results showed that FP could transfect and suppress miR-135b expression in vivo, confirming the tumor-targeting properties of FP. The capacity of biologically produced gold nanoparticles to conjugate with multiple decorative molecules while retaining their stability and effective intracellular uptake makes them a promising alternative strategy superior to current drug carriers.

6.
Biochem Cell Biol ; 90(2): 179-87, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22300453

RESUMEN

Silent information regulators are NAD(+)-dependent enzymes that display differential specificity toward acetylated substrates. This report provides first evidence for deacetylation activity of CobB1 in Streptomyces coelicolor. The protein is highly conserved in streptomycetes. The CobB1 protein catalytically removes the acetyl group from acetylated bovine serum albumin. In the absence of NAD+ or when NAD+ was substituted with nicotinamide, deacetylation was stopped. We isolated gene encoding AcetylCoA synthetaseA. The recombinant enzyme produces Acetyl-CoA from acetate. The highest acsA-mRNA level was detected in cells from the exponential phase of growth, and then decreased in transition and stationary phases of growth. Acetylated acsA loses the ability to transfer acetate to CoA. Deacetylation of the enzyme required CobB1, ATP-Mg2, and NAD+. Using specific antibodies against acetylated lys, CobB1, and acsA, we found relationship between level of CobB1 and acetylation of acsA, indicating that CobB1 is involved in regulating the acetylation level of acsA and consequently its activity. It was found that 1-acetyl-tetrahydroxy and 1-acetyl pentahydroxy antraquinone inhibit the deacetylation activity of CobB1.


Asunto(s)
Procesamiento Proteico-Postraduccional , Sirtuinas/química , Streptomyces coelicolor/enzimología , Acetato CoA Ligasa/biosíntesis , Acetato CoA Ligasa/química , Acetato CoA Ligasa/genética , Acetilación , Secuencia de Aminoácidos , Antraquinonas/química , Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/química , Proteínas Bacterianas/aislamiento & purificación , Dominio Catalítico , Secuencia Conservada , Inhibidores Enzimáticos/química , Regulación Bacteriana de la Expresión Génica , Datos de Secuencia Molecular , Proteínas Recombinantes/antagonistas & inhibidores , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Alineación de Secuencia , Sirtuinas/antagonistas & inhibidores , Sirtuinas/biosíntesis , Streptomyces coelicolor/crecimiento & desarrollo , Streptomyces coelicolor/metabolismo , Transcripción Genética
7.
Fungal Biol ; 126(11-12): 752-763, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36517143

RESUMEN

Ergot, the genus Claviceps comprises several deeply diverged lineages, recently classified as sections. Among them, the section Pusillae, is the most speciose, with a centre of distribution in Africa but occurring worldwide, often as a consequence of its invasive potential. This section includes the most severe plant pathogens such as Claviceps africana and C. gigantea, responsible for toxicoses and a significant reduction in the seed yields of Sorghum and Zea. In this study we surveyed ergot diversity in South Africa, focusing on grasses native to this region, but known for their high potential of invasiveness. The revision based on molecular and phenotypic markers revealed 16 species, with a high proportion of undescribed diversity, confirming Africa as a hot spot for this section. Five new species, Claviceps tulasnei, Claviceps eulaliae, Claviceps hypertheliae, Claviceps fredericksoniae and Claviceps arundinellae were described from Setaria, Eulalia, Hyperthelia, Miscanthus and Arundinella respectively. Claviceps texensis infecting Cenchrus, previously only identified from the same host in Texas, USA, was confirmed to be present in Africa, which is assumed to be its primary area of distribution. In addition, the host grass genus Anthephora is newly reported as a host of Claviceps digitariae. The most of the taxa were negligible concerning alkaloid production, with the exception of C. fredericksoniae, which is a sister of potent alkaloid producer C. africana, and produces mainly DH-ergosine, together with traces of DH-ergocornine. The host/parasite associations within Pusillae section is very narrow, suggesting that co-speciation is the major speciation driver in this group. Host grasses of the described species are already recognised invasive species and their ovarial parasites need to be monitored. This is highlighted by the fact that all Pusillae produced air-borne secondary conidia, which is autapomorphy of this section and considered to be important for their invasive abilities.


Asunto(s)
Claviceps , Alcaloides de Claviceps , Humanos , Claviceps/genética , Poaceae , Sudáfrica , Pueblo Africano
8.
Toxins (Basel) ; 11(8)2019 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-31349616

RESUMEN

Ergot, fungal genus Claviceps, are worldwide distributed grass pathogens known for their production of toxic ergot alkaloids (EAs) and the great agricultural impact they have on both cereal crop and farm animal production. EAs are traditionally considered as the only factor responsible for ergot toxicity. Using broad sampling covering 13 ergot species infecting wild or agricultural grasses (including cereals) across Europe, USA, New Zealand, and South Africa we showed that the content of ergochrome pigments were comparable to the content of EAs in sclerotia. While secalonic acids A-C (SAs), the main ergot ergochromes (ECs), are well known toxins, our study is the first to address the question about their contribution to overall ergot toxicity. Based on our and published data, the importance of SAs in acute intoxication seems to be negligible, but the effect of chronic exposure needs to be evaluated. Nevertheless, they have biological activities at doses corresponding to quantities found in natural conditions. Our study highlights the need for a re-evaluation of ergot toxicity mechanisms and further studies of SAs' impact on livestock production and food safety.


Asunto(s)
Claviceps/química , Alcaloides de Claviceps/toxicidad , Micotoxinas/toxicidad , Xantenos/toxicidad , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Alcaloides de Claviceps/análisis , Células HeLa , Humanos , Células Jurkat , Mitocondrias/efectos de los fármacos , Micotoxinas/análisis , Micotoxinas/farmacología , Xantenos/análisis
9.
Immunol Lett ; 116(1): 79-85, 2008 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-18160138

RESUMEN

Peptides eluted from peripheral blood cells of HLA-B*2705 healthy donor were analyzed by LC MALDI MS/MS and LC ESI FTMS techniques. The sequences of 92 peptide ligands identified from one healthy blood donor by LC MALDI-TOF MS/MS were compared with those previously published from in vitro long-term cell cultures available in SYFPEITHI database and splenocytes. It was found that 18 sequences confirmed within 1ppm mass error by LC ESI FTMS were already described and 3 of them matched with those previously reported from HLA-B*2705 splenocytes. Another 38 sequences validated within the same mass error were not found in SYFPEITHI database and are identified here for the first time. Finally, 36 sequences (5 sequences already published in SYFPEITHI database) were evaluated by LC MALDI-TOF MS/MS but no matches in the list of monoisotopic masses obtained from LC ESI FTMS were found.


Asunto(s)
Antígeno HLA-B27/análisis , Mapeo Peptídico , Péptidos/análisis , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Adulto , Oxidorreductasas de Alcohol , Autoinmunidad/genética , Células Sanguíneas/inmunología , Células Sanguíneas/metabolismo , Bases de Datos de Proteínas , Endopeptidasas/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gs/sangre , Subunidades alfa de la Proteína de Unión al GTP Gs/genética , Subunidades alfa de la Proteína de Unión al GTP Gs/inmunología , Predisposición Genética a la Enfermedad , Antígeno HLA-B27/inmunología , Antígeno HLA-B27/aislamiento & purificación , Proteínas del Choque Térmico HSC70/sangre , Proteínas del Choque Térmico HSC70/genética , Proteínas del Choque Térmico HSC70/inmunología , Histonas/genética , Histonas/metabolismo , Humanos , Masculino , Péptidos/inmunología , Péptidos/aislamiento & purificación , Dominios y Motivos de Interacción de Proteínas , Alineación de Secuencia , Programas Informáticos , Espondilitis Anquilosante/genética , Espondilitis Anquilosante/metabolismo
10.
Mol Vis ; 13: 692-706, 2007 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-17563719

RESUMEN

PURPOSE: The aim of this study was to test whether oligonucleotide-targeted gene repair can correct the point mutation in genomic DNA of PDE6b(rd1) (rd1) mouse retinas in vivo. METHODS: Oligonucleotides (ODNs) of 25 nucleotide length and complementary to genomic sequence subsuming the rd1 point mutation in the gene encoding the beta-subunit of rod photoreceptor cGMP-phosphodiesterase (beta-PDE), were synthesized with a wild type nucleotide base at the rd1 point mutation position. Control ODNs contained the same nucleotide bases as the wild type ODNs but with varying degrees of sequence mismatch. We previously developed a repeatable and relatively non-invasive technique to enhance ODN delivery to photoreceptor nuclei using transpalpebral iontophoresis prior to intravitreal ODN injection. Three such treatments were performed on C3H/henJ (rd1) mouse pups before postnatal day (PN) 9. Treatment outcomes were evaluated at PN28 or PN33, when retinal degeneration was nearly complete in the untreated rd1 mice. The effect of treatment on photoreceptor survival was evaluated by counting the number of nuclei of photoreceptor cells and by assessing rhodopsin immunohistochemistry on flat-mount retinas and sections. Gene repair in the retina was quantified by allele-specific real time PCR and by detection of beta-PDE-immunoreactive photoreceptors. Confirmatory experiments were conducted using independent rd1 colonies in separate laboratories. These experiments had an additional negative control ODN that contained the rd1 mutant nucleotide base at the rd1 point mutation site such that the sole difference between treatment with wild type and control ODN was the single base at the rd1 point mutation site. RESULTS: Iontophoresis enhanced the penetration of intravitreally injected ODNs in all retinal layers. Using this delivery technique, significant survival of photoreceptors was observed in retinas from eyes treated with wild type ODNs but not control ODNs as demonstrated by cell counting and rhodopsin immunoreactivity at PN28. Beta-PDE immunoreactivity was present in retinas from eyes treated with wild type ODN but not from those treated with control ODNs. Gene correction demonstrated by allele-specific real time PCR and by counts of beta-PDE-immunoreactive cells was estimated at 0.2%. Independent confirmatory experiments showed that retinas from eyes treated with wild type ODN contained many more rhodopsin immunoreactive cells compared to retinas treated with control (rd1 sequence) ODN, even when harvested at PN33. CONCLUSIONS: Short ODNs can be delivered with repeatable efficiency to mouse photoreceptor cells in vivo using a combination of intravitreal injection and iontophoresis. Delivery of therapeutic ODNs to rd1 mouse eyes resulted in genomic DNA conversion from mutant to wild type sequence, low but observable beta-PDE immunoreactivity, and preservation of rhodopsin immunopositive cells in the outer nuclear layer, suggesting that ODN-directed gene repair occurred and preserved rod photoreceptor cells. Effects were not seen in eyes treated with buffer or with ODNs having the rd1 mutant sequence, a definitive control for this therapeutic approach. Importantly, critical experiments were confirmed in two laboratories by several different researchers using independent mouse colonies and ODN preparations from separate sources. These findings suggest that targeted gene repair can be achieved in the retina following enhanced ODN delivery.


Asunto(s)
Hidrolasas Diéster Fosfóricas/genética , Mutación Puntual , Degeneración Retiniana/genética , Degeneración Retiniana/terapia , Reparación del Gen Blanco , Envejecimiento/metabolismo , Animales , Animales Recién Nacidos , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 6 , Ojo/enzimología , Inmunohistoquímica/métodos , Iontoforesis , Ratones , Ratones Endogámicos C3H , Ratones Mutantes , Oligonucleótidos/administración & dosificación , Oligonucleótidos/uso terapéutico , Hidrolasas Diéster Fosfóricas/metabolismo , Retina/enzimología , Retina/patología , Degeneración Retiniana/enzimología , Degeneración Retiniana/metabolismo , Rodopsina/metabolismo , Coloración y Etiquetado
11.
J Plant Physiol ; 164(2): 174-84, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16436306

RESUMEN

Olive plants produce both sucrose and mannitol as major photosynthetic products. Contrary to previously studied celery [Vítová et al., Mannitol utilisation by celery (Apium graveolens) plants grown under different conditions in vitro. Plant Sci 2002; 163: 907-16], in vitro these carbohydrates were found to be able to sustain growth of olive shoots roughly to the same extent at all tested concentrations (1-9% w/v). We studied the involvement of the particular components of the endogenous carbohydrate spectrum in response to different abiotic stresses (osmotic stress, salinity, low temperature) in vitro. Salinity (100mM NaCl) caused a decrease of total soluble carbohydrates, while an increase was observed during low-temperature treatment (0 and 4 degrees C). Mannitol accumulated primarily under salinity (up to 40% of total soluble carbohydrates compared to 10-20% in controls). Only a small (two-fold) increase of proline content in salinity stressed plants indicates proline does not play a significant role in olive stress response. Low temperature led to an increase of the raffinose family oligosaccharides (RFO) proportion in total carbohydrates. We conclude that olive plants exploit the high diversity of the carbohydrate spectrum in specific response to different stresses.


Asunto(s)
Adaptación Fisiológica , Metabolismo de los Hidratos de Carbono , Olea/metabolismo , Brotes de la Planta/metabolismo , Ácido Abscísico/fisiología , Frío , Técnicas de Cultivo , Manitol/metabolismo , Olea/crecimiento & desarrollo , Olea/fisiología , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/fisiología , Prolina/metabolismo , Cloruro de Sodio/metabolismo , Sacarosa/metabolismo , Agua/fisiología
12.
Oncotarget ; 8(61): 103137-103153, 2017 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-29262552

RESUMEN

Abnormalities in cancer metabolism represent potential targets for cancer therapy. We have recently identified a natural compound Quambalarine B (QB), which inhibits proliferation of several leukemic cell lines followed by cell death. We have predicted ubiquinone binding sites of mitochondrial respiratory complexes as potential molecular targets of QB in leukemia cells. Hence, we tracked the effect of QB on leukemia metabolism by applying several omics and biochemical techniques. We have confirmed the inhibition of respiratory complexes by QB and found an increase in the intracellular AMP levels together with respiratory substrates. Inhibition of mitochondrial respiration by QB triggered reprogramming of leukemic cell metabolism involving disproportions in glycolytic flux, inhibition of proteins O-glycosylation, stimulation of glycine synthesis pathway, and pyruvate kinase activity, followed by an increase in pyruvate and a decrease in lactate levels. Inhibition of mitochondrial complex I by QB suppressed folate metabolism as determined by a decrease in formate production. We have also observed an increase in cellular levels of several amino acids except for aspartate, indicating the dependence of Jurkat (T-ALL) cells on aspartate synthesis. These results indicate blockade of mitochondrial complex I and II activity by QB and reduction in aspartate and folate metabolism as therapeutic targets in T-ALL cells. Anti-cancer activity of QB was also confirmed during in vivo studies, suggesting the therapeutic potential of this natural compound.

13.
Immunol Lett ; 103(2): 135-41, 2006 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-16313971

RESUMEN

HLA-B27 is a relative risk factor for ankylosing spondylitis (AS) and is present in about 10% in European populations but in 95% of AS patients. Various data suggest that the HLA-B27 molecule itself could be the strongest risk factor, but there is no explanation for this association. To define differential antigen presenting features of HLA-B27 in healthy individuals and AS patients, a question that cannot be addressed by biochemical studies on cell lines, the HLA-B27 protein was purified from peripheral blood lymphocytes of AS patients and healthy controls and pool sequencing of the bound peptides was performed. Results show that peptides are rich in proline (Pro) and the content of arginine (Arg) is much lower in comparison with sequences listed in the register of peptides eluted from cell cultures. Statistically significant differences were detected in frequencies of a subset of amino acids, predominantly at positions in the middle of the peptides. The frequency of Glu was increased and Gln was decreased in peptides from AS patients. Detailed analysis of purity of the immunoisolated HLA molecules excluded that the peptides might originate from any co-purified HLA molecules other than B27. We conclude that statistically significant increase in the Glu/Gln ratio of peptides from AS patients, consistent with increased deamidation in vivo, may account for differential antigenicity of HLA-B27 in patients. Source protein(s) of deamidated peptides remain unknown.


Asunto(s)
Antígeno HLA-B27/genética , Fragmentos de Péptidos/genética , Espondilitis Anquilosante/genética , Adulto , Arginina/genética , Femenino , Ácido Glutámico/genética , Glutamina/genética , Antígeno HLA-B27/química , Humanos , Masculino , Fragmentos de Péptidos/química , Prolina/genética , Factores de Riesgo , Análisis de Secuencia de Proteína
14.
Fungal Biol ; 120(8): 917-930, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27521625

RESUMEN

Results of a survey and study of the Claviceps purpurea group of species in South Africa are being presented and five new species are described. Morphological descriptions are based on the anamorphs and four nuclear genetic loci. Claviceps fimbristylidis sp. nov. on Fimbristylis complanata was discovered wide-spread across five provinces of the country associated with water and represents the fourth Claviceps species recorded from the Cyperaceae. Claviceps monticola sp. nov. is described from Brachypodium flexum growing in mountain forests in Mpumalanga Province, as well as the northern Drakensberg southwards into the Eastern Cape Province. Claviceps pazoutovae sp. nov. is recorded from Stipa dregeana var. dregeana and Ehrharta erecta var. erecta, also associated with these mountain ranges. Claviceps macroura sp. nov. is recorded from Cenchrus macrourus from the Eastern Cape and Claviceps capensis sp. nov. from Ehrharta villosa var. villosa is recorded from the Western Cape Province. Claviceps cyperi, only recorded from South Africa is included in the study. Ergot alkaloid profiles of all species are provided and showed similarity to C. purpurea. Only C. cyperi and in lesser degree C. capensis, C. macroura, and C. pazoutovae produced ergot alkaloids in clinically significant amounts. Several reported species infect invasive grass species, native to South Africa, and thus represent potentially invasive species.


Asunto(s)
Claviceps/clasificación , Claviceps/aislamiento & purificación , Microbiología Ambiental , Alcaloides de Claviceps/análisis , Cromatografía Líquida de Alta Presión , Claviceps/química , Claviceps/genética , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Bosques , Componente 7 del Complejo de Mantenimiento de Minicromosoma/genética , Factor 1 de Elongación Peptídica/genética , Filogenia , Análisis de Secuencia de ADN , Sudáfrica , Tubulina (Proteína)/genética , Agua
15.
Sci Rep ; 6: 33200, 2016 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-27620349

RESUMEN

Pathogenic and non-pathogenic related microorganisms differ in secondary metabolite production. Here we show that riboflavin overproduction by a fungal pathogen and its hyperaccumulation in affected host tissue exacerbates a skin infection to necrosis. In white-nose syndrome (WNS) skin lesions caused by Pseudogymnoascus destructans, maximum riboflavin concentrations reached up to 815 µg ml(-1), indicating bioaccumulation and lack of excretion. We found that high riboflavin concentrations are cytotoxic under conditions specific for hibernation, affect bats' primary fibroblasts and induce cell detachment, loss of mitochondrial membrane potential, polymerization of cortical actin, and cell necrosis. Our results explain molecular pathology of WNS, where a skin infection becomes fatal. Hyperaccumulation of vitamin B2 coupled with reduced metabolism and low tissue oxygen saturation during hibernation prevents removal of excess riboflavin in infected bats. Upon reperfusion, oxygen reacts with riboflavin resulting in dramatic pathology after arousal. While multiple molecules enable invasive infection, riboflavin-associated extensive necrosis likely contributes to pathophysiology and altered arousal pattern in infected bats. Bioaccumulation of a vitamin under natural infection represents a novel condition in a complex host-pathogen interplay.


Asunto(s)
Ascomicetos/patogenicidad , Quirópteros/microbiología , Dermatomicosis/microbiología , Riboflavina/metabolismo , Alas de Animales/microbiología , Animales , Ascomicetos/clasificación , Ascomicetos/genética , Adhesión Celular , Células Cultivadas , Fibroblastos/citología , Fibroblastos/metabolismo , Fibroblastos/microbiología , Interacciones Huésped-Patógeno , Potencial de la Membrana Mitocondrial , Microscopía Electrónica , Filogenia , Factores de Virulencia/metabolismo , Alas de Animales/citología , Alas de Animales/ultraestructura
16.
Folia Microbiol (Praha) ; 60(3): 259-67, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25416512

RESUMEN

A strain of Biatriospora sp. CCF 4378 was tested for the production of secondary metabolites under submerged fermentation conditions. Eleven compounds were isolated from the culture broth, and the structures of these compounds were determined using HRMS, NMR and X-ray analysis. In addition to six known naphthoquinone derivatives, i.e. ascomycone A, ascomycone B, 6-deoxyfusarubine, 6-deoxyanhydrofusarubine, herbarine and balticol A, one derivative of 2-azaanthraquinone, 6-deoxybostrycoidine, was also identified. Four new natural pyranonaphthoquinones were found, and these natural products were pleorubrin A, pleorubrin B, pleorubrin C and pleorubrin D. The toxicity on human cell lines of the crude naphthoquinone fraction and pure 6-deoxybostrycoidin, ascomycone B, pleorubrin B and 6-deoxyfusarubin was tested. Ascomycone B and 6-deoxyfusarubin elicited rapid cytotoxicity at micromolar concentrations.


Asunto(s)
Ascomicetos/aislamiento & purificación , Ascomicetos/metabolismo , Endófitos/aislamiento & purificación , Endófitos/metabolismo , Naftoquinonas/química , Naftoquinonas/metabolismo , Ulmus/microbiología , Ascomicetos/clasificación , Ascomicetos/genética , Línea Celular , Supervivencia Celular/efectos de los fármacos , Endófitos/clasificación , Endófitos/genética , Humanos , Estructura Molecular , Naftoquinonas/farmacología
17.
PLoS One ; 10(2): e0118913, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25723150

RESUMEN

Four strains of the fungus Quambalaria cyanescens (Basidiomycota: Microstromatales), were used for the determination of secondary metabolites production and their antimicrobial and biological activities. A new naphthoquinone named quambalarine A, (S)-(+)-3-(5-ethyl-tetrahydrofuran-2-yliden)-5,7,8-trihydroxy-2-oxo-1,4-naphthoquinone (1), together with two known naphthoquinones, 3-hexanoyl-2,5,7,8-tetrahydroxy-1,4-naphthoquinone (named here as quambalarine B, 2) and mompain, 2,5,7,8-tetrahydroxy-1,4-naphthoquinone (3) were isolated. Their structures were determined by single-crystal X-ray diffraction crystallography, NMR and MS spectrometry. Quambalarine A (1) had a broad antifungal and antibacterial activity and is able inhibit growth of human pathogenic fungus Aspergillus fumigatus and fungi co-occurring with Q. cyanescens in bark beetle galleries including insect pathogenic species Beauveria bassiana. Quambalarine B (2) was active against several fungi and mompain mainly against bacteria. The biological activity against human-derived cell lines was selective towards mitochondria (2 and 3); after long-term incubation with 2, mitochondria were undetectable using a mitochondrial probe. A similar effect on mitochondria was observed also for environmental competitors of Q. cyanescens from the genus Geosmithia.


Asunto(s)
Basidiomycota/metabolismo , Productos Biológicos/metabolismo , Fermentación , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/metabolismo , Antiinfecciosos/farmacología , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Productos Biológicos/farmacología , Línea Celular , Humanos , Pruebas de Sensibilidad Microbiana
18.
Immunol Lett ; 94(3): 261-5, 2004 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-15275975

RESUMEN

The sequences and profiles of peptides which bind to HLA-B*2705 splenocytes and peripheral blood cells were compared with those previously published from in vitro long-term cell cultures. B*2705 peptide profile analysed by solid-phase Edman degradation and 15 individual peptide sequences determined by LC-MS/MS were partially similar to those defined from in vitro long-term cell cultures. Arg at P2 was found in 11 of 15 sequenced peptides (73.3%). This value is lower in comparison with other published data. Two sequences were matching to unknown proteins, which displayed similarity with myosin. These are first data on peptide sequences isolated directly from HLA-B27 molecules without prior in vitro propagation of the cells.


Asunto(s)
Antígeno HLA-B27/química , Antígeno HLA-B27/inmunología , Linfocitos/inmunología , Fragmentos de Péptidos/química , Bazo/inmunología , Células Cultivadas , Humanos , Fragmentos de Péptidos/inmunología
19.
J Antibiot (Tokyo) ; 64(11): 717-22, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21915134

RESUMEN

A new polyene macrolide family, closely related to the pentaene macrolide antibiotic roflamycoin, was isolated from the both fermentation broth and biomass of Streptomyces durmitorensis wild-type strain MS405. The main compound was identified by NMR and Fourier transform ion cyclotron resonance mass spectrometry as 32,33-didehydroroflamycoin (1; DDHR). Additional four structurally related compounds were determined solely by MS analysis. DDHR induces cell death by apoptosis in various cancer cell lines as demonstrated by DNA fragmentation. Striking feature of DDHR is its internal fluorescence allowing visualization of labeled plasma membranes and internal membrane structures.


Asunto(s)
Antineoplásicos/metabolismo , Macrólidos/metabolismo , Polienos/metabolismo , Streptomyces/metabolismo , Antineoplásicos/química , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Membrana Celular/química , Membrana Celular/metabolismo , Fluorescencia , Humanos , Macrólidos/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Modelos Moleculares , Estructura Molecular , Polienos/química , Coloración y Etiquetado
20.
J Chromatogr A ; 1217(40): 6296-302, 2010 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-20801456

RESUMEN

Lilac coloured species of Geosmithia lavendula produce a mixture of polyhydroxylated anthraquinones under condition of submerged fermentation. Three pigments had been isolated and identified earlier as a 1,3,6,8-tetrahydroxyanthraquinone (compound 7), rhodolamprometrin (1-acetyl 2,4,5,7-tetrahydroxyanthraquinone; compound 5), and 1-acetyl 2,4,5,7,8-penthahydroxyanthraquinone (compound 4). A new HPLC method was developed for the separation of three known and ten new anthraquinone pigments. In addition, five new pigments were determined by FTMS as coeluting impurities. The analyses were performed on a reversed phase column using gradient elution with a mobile phase system consisting of phosphate buffer (50 mM; pH=2.0) and acetonitrile. The structure evaluation was based namely on FTMS and UV-VIS spectrometry. The developed procedure was used for the determination of individual anthraquinones in fermentation broth of G. lavendula after 14 days of cultivation. The extractable amount and LOQ (both in µg ml(-1)) for the two main pigments from G. lavendula are 50.02 and 2.15 for compound 4, and 63.77 and 2.75, for compound 5, respectively.


Asunto(s)
Antraquinonas/análisis , Cromatografía Líquida de Alta Presión/métodos , Hypocreales/química , Espectrometría de Masas en Tándem/métodos , Antraquinonas/química , Cromatografía de Fase Inversa , Fermentación , Modelos Lineales , Metanol , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
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