Benzothiazole based cyanine dyes with bridged groups in the pentamethine chain were studied as potential far-red fluorescent probes for protein detection. Spectral-luminescent properties were ...characterized for unbound dyes and in the presence of serum albumins (bovine (BSA), human (HSA), equine (ESA)), and globular proteins (β-lactoglobulin, ovalbumin). We have observed that the addition of albumins leads to a significant increase in dyes fluorescence intensity. However, the fluorescent response of dyes in the presence of other globular proteins was notably lower. The value of fluorescence quantum yield for dye bearing a sulfonate group complexed with HSA amounted to 42% compared with 0.2% for the free dye. The detection limit of HSA by this dye was greater than 0.004 mg ml
−1
which indicates the high sensitivity of dye to low HSA concentrations. Modelling of structure of the dyes complexes with albumin molecules was performed by molecular docking. According to these data, dyes could bind to up to five sites on the HSA molecule; the most preferable are the haemin-binding site in subdomain IB and the dye-binding site in the pocket between subdomains IA, IIA and IIIA. This work confirms that pentamethine cyanine dyes could be proposed as powerful far-red fluorescent probes applicable for highly sensitive detection of albumins.
Protein kinase FGFR1 inhibitors: We report a series of N-phenylthieno2,3-dpyrimidin-4-amines as a novel class of nanomolar-range FGFR1 inhibitors. These new FGFR1 inhibitors showed a good selectivity ...and antiproliferative activity on cancer cell line. Display omitted
Fibroblast grow factor receptor 1 (FGFR1) is an important anti-cancer target that plays crucial role in oncogenesis and oncogenic angiogenesis. The structure–activity relationship (SAR) of N-phenylthieno2,3-dpyrimidin-4-amines was investigated. Binding of active compounds with FGFR1 kinase was analyzed by molecular modeling studies. Selected active thieno2,3-dpyrimidines were tested for selectivity and antiproliferative activity. The most active compounds, 3-({6-phenylthieno2,3-dpyrimidin-4-yl}amino)phenol and 3-({5-phenylthieno2,3-dpyrimidin-4-yl}amino)phenol have IC50 0.16 and 0.18μM, respectively. The results presented here may help to identify new thienopyrimidines with optimized cell growth inhibitory activity which may be further used as anticancer agents.
A series of homodimer styrylcyanine dyes based on (
p-dimethylaminostyryl)pyridinium, (
p-dimethylaminostyryl)benzoxazolium, (
p-dimethylaminostyryl)benzothiazolium, (
...p-dimethylaminostyryl)-1,3,3-trimethyl-3
H-indolium residues were synthesized. Spectral-luminescent properties of the obtained homodimers in free state and in the presence of nucleic acids and BSA were studied. Homodimer styrylcyanines with the length of linkage group of 2 or more carbon atoms demonstrated a DNA-binding preference. Significant long-wave shifts of fluorescence and emission maxima of dyes with short linkage group could be explained by the interaction between chromophores due to the short distance between them, as it is the case for molecular aggregates. Homodimer dyes based on the (
p-dimethylaminostyryl)pyridinium residue having linkage group of 5 or more carbon atoms interact with dsDNA with significant emission increase and could be used as DNA specific fluorescent probes.
Firstly, fluorescent cyanine dyes (monomethine T-284 and trimethine SH-516) are proposed for selective fluorescent detection of fibrillar α-synuclein. Studies of interaction mode of dyes with ...aggregated protein are presented.
With the aim of searching of novel amyloid-specific fluorescent probes the ability of series of mono- and trimethine cyanines based on benzothiazole, pyridine and quinoline heterocycle end groups to recognize fibrillar formations of α-synuclein (ASN) was studied. For the first time it was revealed that monomethine cyanines can specifically increase their fluorescence in aggregated ASN presence. Dialkylamino-substituted monomethine cyanine T-284 and meso-ethyl-substituted trimethine cyanine SH-516 demonstrated the higher emission intensity and selectivity to aggregated ASN than classic amyloid stain Thioflavin T, and could be proposed as novel efficient fluorescent probes for fibrillar ASN detection. Studies of structure–function dependences have shown that incorporation of amino- or diethylamino- substituents into the 6-position of the benzothiazole heterocycle yields in a appearance of a selective fluorescent response to fibrillar α-synuclein presence. Performed calculations of molecular dimensions of studied cyanine dyes gave us the possibility to presume, that dyes bind with their long axes parallel to the fibril axis via insertion into the neat rows (so called ‘channels’) running along fibril.
La prevalencia de infección por virus Papiloma Humano (VPH) es desconocida en niños, niñas y adolescentes (NNA) chilenos. En 2014 se incorporó en Chile la vacuna VPH al Programa Nacional de ...Inmunizaciones en niñas y en varones el 2019. Objetivo: Determinar la prevalencia, genotipos y características de la infección por VPH en NNA con lesiones anogenitales no vacunados contra VPH. Pacientes y Método: Se estudiaron NNA con lesiones anogenitales que consultaron en el Hospital Calvo Mackenna entre 2013 y 2017. Se registró motivo de consulta, edad, sexo, antecedentes de familiar portador de lesiones por VPH, antecedente de vulneración sexual, y actividad sexual consentida. Se detectó VPH por PCR y tipificación mediante hibridación reversa en línea del gen L1. Las muestras se analizaron en la Sección de Virus Oncogénicos del Instituto de Salud Pública. Resultados: Se estudiaron 110 pacientes; 44.5% niños/as. Se detectó VPH en 34 (30,9% IC95% 22,4- 40,4); 22 (44,9%) niños/as y 12 (19,7%) adolescentes. Once (91,7%) adolescentes tenían antecedente de contacto sexual (p < 0,005); 4 (18,2%) niños/as develaron vulneración sexual. 25% de las lesiones genitales y 50% de las perianales eran VPH (+) (p 0,015). Los genotipos más frecuentes fueron 59, 58, 16, 18, 6 y 11. En niños/as se detectó sólo genotipos de bajo riesgo. En 91.7% de las adolescentes VPH (+) se detectaron genotipos de alto riesgo. Conclusión: La prevalencia de infección por VPH fue 30%. En adolescentes la infección estuvo relacionada a contacto sexual y a VPH de alto riesgo. En niños/as se asoció a genotipos de bajo riesgo. Las lesiones perianales se asociaron con mayor frecuencia que las genitales a infección por VPH. La inspección visual no permite precisar la etiología de las lesiones genitales, por lo que es necesario realizar test de PCR para virus papiloma humano.
Aim. To identify novel FGFR1 inhibitors using virtual screening approach. Methods. We used methods of organic synthesis, molecular docking via the Autodock 4.2.6 program package and in vitro ...biochemical tests with γ-32P. Results. In vitro experiments showed that 9 of 23 tested compounds possess inhibitory activity against FGFR1 with IC50 values in the range from 0.9 to 5.6 μM. Conclusions. Nine FGFR1 inhibitors were developed. The mode of compounds binding with the ATP-acceptor site was determined using molecular docking methods and the dependence of the compounds’ activity on the substituents R1, R4 and R5 was evaluated
The imidazo1,2-
apyridinium heterocyclic system was used to prepare styryl dyes. Improved synthetic methods were proposed for the parent imidazo1,2-
apyridines and their corresponding quaternary ...salts. The standard method for preparing styrylcyanines was modified for the synthesis of the target imidazo1,2-
apyridinium dyes. Spectral-luminescent properties of the obtained dyes in free state and in the presence of nucleic acids, BSA, and BSA/detergent system were studied. 7-2-(4-Dihexylaminophenyl)-1-ethenyl-2-(2,4-dimethoxyphenyl)-1-ethylimidazo1,2-
apyridin-1-ium iodide (SIP-8) containing C
6 aliphatic tails and 2,4-methoxy substituents in the 2-phenyl ring exhibited specificity to BSA.
Methyltransferases form a large class of enzymes, most of which use
S-adenosylmethionine as the methyl donor. In fact,
S-adenosylmethionine is second only to ATP in the variety of reactions for which ...it serves as a cofactor. Several methods to measure methyltransferase activity have been described, most of which are applicable only to specific enzymes and/or substrates. In this work we describe a sensitive liquid chromatography/mass spectroscopy-based methyltransferase assay. The assay monitors the conversion of
S-adenosylmethionine to
S-adenosylhomocysteine and can be applied to any methyltransferase and substrate of interest. We used the well-characterized enzyme catechol
O-methyltransferase to demonstrate that the assay can monitor activity with a variety of substrates, can identify new substrates, and can be used even with crude preparation of enzyme. Furthermore, we demonstrate the utility of the assay for kinetic characterization of enzymatic activity.
A series of novel 4-oxo-4,6,7,8-tetrahydropyrrolo1,2-
athieno2,3-
dpyrimidinium and 5-oxo-1,2,3,5-tetrahydropyrrolo2,1-
bquinazolinium styryl dyes were synthesized. For preparing of studied dyes the ...standard method of styrylcyanines synthesis was modified. Spectral–luminescent properties of obtained dyes in free state and in the presence of nucleic acids and BSA were studied. It was shown that
p-dimethylaminostyryls based on 4-oxo-4,6,7,8-tetrahydropyrrolo1,2-
athieno2,3-
dpyrimidinium with aliphatic substituents in 2 and 3 positions demonstrated RNA-binding preference. These dyes in the presence of RNA significantly enhance emission intensity and could be used as RNA-specific fluorescent probes. Besides, the fluorescence emission after two-photon absorption of dye–RNA complexes in buffer solutions was measured.
PDF
