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1.
Molecules ; 23(5)2018 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-29783733

RESUMO

Alkaloids compose a large class of natural products, and mono-methylated polyamines are a common intermediate in their biosynthesis. In order to evaluate the role of selectively methylated natural products, synthetic strategies are needed to prepare them. Here, N-methylcadaverine is prepared in 37.3% yield in three steps. The alternative literature two-step strategy resulted in reductive deamination to give N-methylpiperidine as determined by the single crystal structure. A straightforward strategy to obtain the mono-alkylated aliphatic diamine, cadaverine, which avoids potential side-reactions, is demonstrated.


Assuntos
Poliaminas Biogênicas/síntese química , Cadaverina/química , Piperidinas/síntese química , Poliaminas Biogênicas/química , Cristalografia por Raios X , Ciclização , Metilação , Modelos Moleculares , Estrutura Molecular , Piperidinas/química
2.
Org Lett ; 20(8): 2420-2423, 2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-29624063

RESUMO

The extension of the family of dyn[ n]arenes toward a three-membered macrocycle is reported. Through a templated approach, a single diastereoisomer of a dyn[3]arene that bears six carboxyl groups could be isolated by precipitation in 59-63% yield and excellent purity (≥95%). A combination of experimental and computational experiments in water at physiological pH revealed that the macrocycle could bind parent biogenic polyamines with a unique diversity of surface-binding modes. Whereas no binding event could be accurately measured with 1,3-diaminopropane, spermidine formed a classical stoichiometric complex with the dyn[3]arene in the millimolar concentration range. On the other hand, the data obtained for spermine could only be attributed to a more complex binding event with the formation of a 2:1 complex at high [host]/[guest] ratios and redistribution toward a 1:1 complex upon further addition of guest.


Assuntos
Poliaminas Biogênicas/química , Estrutura Molecular , Estereoisomerismo , Água
3.
Plant Physiol Biochem ; 125: 205-211, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29475086

RESUMO

Siliceous frustules of diatom algae contain unique long-chain polyamines, including those having more than six nitrogen atoms. These polyamines participate in the formation of the siliceous frustules of the diatoms but their precise physiological role is not clear. The main hypotheses include formation of a polyamine and polyphosphate supramolecular matrix. We have synthesized novel fluorescent dyes from a synthetic oligomeric mixture of polyamines and the fluorophore 7-nitro-2,1,3-benzoxadiazole. The long polyamine chain ensures the high affinity of these dyes to silica, which allows their application in the staining of siliceous materials, such as valves of diatom algae and fossilized samples from sediments. The fluorescently stained diatom valves were found to be promising liquid flow tracers in hydrodynamic tests. Furthermore, complexation of the polyamine component of the dyes with carbonic polymeric acids results in changes to the visible spectrum of the fluorophore, which allows study of the stability of the complex vs the length of the polyamine chain. Using poly (vinyl phosphonic acid) as a model for phosphate functionality in silaffins (a potential matrix in the formation of biogenic silica) little complexation with the polyamine fluorophores was observed, bringing into question the role of a polyamine - polymeric phosphate matrix in biosilicification.


Assuntos
4-Cloro-7-nitrobenzofurazano/química , Poliaminas Biogênicas , Diatomáceas , Corantes Fluorescentes/química , Coloração e Rotulagem/métodos , Poliaminas Biogênicas/química , Poliaminas Biogênicas/metabolismo , Diatomáceas/citologia , Diatomáceas/metabolismo
4.
Int J Biol Macromol ; 112: 175-178, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29414728

RESUMO

We have performed a biophysical characterization, at single molecule level, of the interaction between the DNA molecule and the biogenic polyamine putrescine. By using force spectroscopy, we were able to monitor the complexes formation as putrescine is added to the sample, determining the mechanical properties of such complexes and the physicochemical (binding) parameters of the interaction for three different ionic strengths. In particular, it was shown that the behavior of the equilibrium binding constant as a function of the counterion concentration deviates from the prediction of the Record-Lohman model. The measured constants were (1.3 ± 0.2) × 105 M- 1 for [Na] = 150 mM, (2.1 ± 0.2) × 105 M- 1 for [Na] = 10 mM, and (2.2 ± 0.3) × 105 M- 1 for [Na] = 1 mM. The cooperativity degree of the binding reaction, on the other hand, increases with the ionic strength. From these analysis, the DNA-putrescine binding mechanisms are inferred, and a comparison with results reported for ordinary bivalent ions like magnesium is performed. Such study provides new insights on the general behavior of the DNA interactions with biogenic polyamines.


Assuntos
Poliaminas Biogênicas/química , Proteínas de Ligação a DNA/química , DNA/química , Nanotecnologia , Sítios de Ligação , Fenômenos Biofísicos , Modelos Moleculares , Conformação de Ácido Nucleico , Concentração Osmolar , Espermidina/química , Espermina/química
5.
Carbohydr Polym ; 152: 665-671, 2016 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-27516317

RESUMO

We report the conjugation of chitosan nanoparticles with biogenic polyamines spermine (spm), spermidine (spmd) and synthetic polyamines 3,7,11,15-tetrazaheptadecane.4HCl (BE-333) in aqueous solution. Multiple spectroscopic methods, thermodynamic parameters and molecular modeling were used to analyse polyamine bindings to chitosan nanoparticles. Thermodynamic parameters ΔS, ΔH and ΔG showed that polyamines bind protein through H-bonding and hydrophobic contacts with biogenic polyamines form more stable conjugates than synthetic polyamines. As polymer size increases the stability of polyamine-chitosan conjugate increases. The loading efficacy was 40-50% for polyamine-chitosan conjugates. Modeling showed that polyamine-protein interaction is spontaneous and chitosan nanoparticles can be used for delivery of antitumor polyamine analogues.


Assuntos
Antineoplásicos , Poliaminas Biogênicas , Quitosana/química , Nanopartículas/química , Antineoplásicos/síntese química , Antineoplásicos/química , Poliaminas Biogênicas/síntese química , Poliaminas Biogênicas/química , Sistemas de Liberação de Medicamentos
6.
Int J Biol Macromol ; 92: 515-522, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27431795

RESUMO

We have reviewed the conjugation of biogenic polyamines spermine (spm), spermidine (spmd) and synthetic polyamines 3,7,11,15-tetrazaheptadecane.4HCl (BE-333) and 3,7,11,15,19-pentazahenicosane.5HCl (BE-3333) with human serum albumin (HSA), bovine serum albumin (BSA) and milk beta-lactoglobulin (b-LG) in aqueous solution at physiological pH. The results of multiple spectroscopic methods and molecular modeling were analysed here and correlations between polyamine binding mode and protein structural changes were estabilished. Polyamine-protein bindings are mainly via hydrophilic and H-bonding contacts. BSA forms more stable conjugates than HSA and b-LG. Biogenic polyamines form more stable complexes than synthetic polyamines except in the case of b-LG, where the protein shows more hydrophobic character than HSA and BSA. The loading efficacies were 40-52%. Modeling showed the presence of several H-bonding systems, which stabilized polyamine-protein conjugates. Polyamine conjugation induced major alterations of serum protein conformations. The potential application of serum proteins in delivery of polyamines is evaluated here.


Assuntos
Poliaminas Biogênicas/metabolismo , Albumina Sérica/metabolismo , Aminoácidos/química , Animais , Sítios de Ligação , Poliaminas Biogênicas/química , Bovinos , Humanos , Concentração de Íons de Hidrogênio , Cinética , Lactoglobulinas/metabolismo , Simulação de Acoplamento Molecular , Estrutura Secundária de Proteína , Albumina Sérica/química , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Int J Biochem Cell Biol ; 76: 87-97, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27163532

RESUMO

Spermidine acetyltransferase (SAT) from Escherichia coli, which catalyses the transfer of acetyl groups from acetyl-CoA to spermidine, is a key enzyme in controlling polyamine levels in prokaryotic cells. In this study, we determined the crystal structure of SAT in complex with spermidine (SPD) and CoA at 2.5Å resolution. SAT is a dodecamer organized as a hexamer of dimers. The secondary structural element and folding topology of the SAT dimer resemble those of spermidine/spermine N(1)-acetyltransferase (SSAT), suggesting an evolutionary link between SAT and SSAT. However, the polyamine specificity of SAT is distinct from that of SSAT and is promiscuous. The SPD molecule is also located at the inter-dimer interface. The distance between SPD and CoA molecules is 13Å. A deep, highly acidic, water-filled cavity encompasses the SPD and CoA binding sites. Structure-based mutagenesis and in-vitro assays identified SPD-bound residues, and the acidic residues lining the walls of the cavity are mostly essential for enzymatic activities. Based on mutagenesis and structural data, we propose an acetylation mechanism underlying promiscuous polyamine recognition for SAT.


Assuntos
Acetiltransferases/química , Poliaminas Biogênicas/química , Proteínas de Escherichia coli/química , Escherichia coli/enzimologia , Multimerização Proteica , Acetilação , Sítios de Ligação , Coenzima A/química , Cristalografia por Raios X , Estrutura Quaternária de Proteína , Especificidade por Substrato
8.
Amino Acids ; 48(10): 2423-31, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27168074

RESUMO

Polyamines are positively charged organic cations under physiologic ionic and pH conditions and hence they interact with negatively charged macromolecules such as DNA and RNA. Although electrostatic interaction is the predominant mode of polyamine-nucleic acid interactions, site- and structure-specific binding has also been recognized. A major consequence of polyamine-DNA interaction is the collapse of DNA to nanoparticles of approximately 100 nm diameter. Electron and atomic force microscopic studies have shown that these nanoparticles are spheroids, toroids and rods. DNA transport to cells for gene therapy applications requires the condensation of DNA to nanoparticles and hence the study of polyamines and related compounds with nucleic acids has received technological importance. In addition to natural and synthetic polyamines, several amine-terminated or polyamine-substituted agents are under intense investigation for non-viral gene delivery vehicles.


Assuntos
Poliaminas Biogênicas , DNA , Técnicas de Transferência de Genes , Terapia Genética/métodos , Nanopartículas/química , Animais , Poliaminas Biogênicas/química , Poliaminas Biogênicas/farmacologia , DNA/química , DNA/farmacologia , Humanos
9.
J Biochem ; 159(5): 509-17, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26721905

RESUMO

Thermus thermophilus is an extreme-thermophilic eubacterium, which grows at a wide range of temperatures (50-83°C). This thermophile produces various polyamines including long and branched polyamines. In tRNAs from T. thermophilus, three distinct modifications, 2'-O-methylguanosine at position 18 (Gm18), 5-methyl-2-thiouridine at position 54 and N(1)-methyladenosine at position 58, are assembled at the elbow region to stabilize the L-shaped tRNA structure. However, the structures of unmodified tRNA precursors are disrupted at high temperatures. We hypothesize that polyamine(s) might have a positive effect on the modification process of unmodified tRNA transcript. We investigated the effects of eight polyamines on Gm18 formation in the yeast tRNA(Phe) transcript by tRNA (Gm18) methyltransferase (TrmH). Higher concentrations of linear polyamines inhibited TrmH activity at 55°C, while optimum concentration increased TrmH activity at 45-75°C. Exceptionally, caldohexamine, a long polyamine, did not show any positive effect on the TrmH activity at 55°C. However, temperature-dependent experiments revealed that 1 mM caldohexamine increased TrmH activity at 60-80°C. Furthermore, 0.25 mM tetrakis(3-aminopropy)ammonium, a branched polyamine, increased TrmH activity at a broad range of temperatures (40-85°C). Thus, caldohexamine and tetrakis(3-aminopropy)ammonium were found to enhance the TrmH activity at high temperatures.


Assuntos
Proteínas de Bactérias/química , Poliaminas Biogênicas/química , Processamento Pós-Transcricional do RNA , RNA Bacteriano/química , RNA de Transferência/química , Thermus thermophilus/química , tRNA Metiltransferases/química , Proteínas de Bactérias/metabolismo , Poliaminas Biogênicas/metabolismo , Temperatura Alta , Metilação , RNA Bacteriano/metabolismo , RNA de Transferência/metabolismo , Thermus thermophilus/metabolismo , tRNA Metiltransferases/metabolismo
10.
J Photochem Photobiol B ; 155: 13-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26722998

RESUMO

We report the thermodynamic analysis of the bindings of poly(amidoamine) (PAMAM-G4) nanoparticles with biogenic polyamines spermine (spm), spermidine (spmd) and synthetic polyamines 3,7,11,15-tetrazaheptadecane·4HCl (BE-333) in aqueous solution at physiological conditions. Multiple spectroscopic methods, thermodynamic parameters and molecular modelling were used to analyse polyamine bindings to PAMAM dendrimers. Thermodynamic parameters ΔS, ΔH and ΔG parameters showed that polyamines bind polymer through H-bonding and van der Waals contacts with biogenic polyamines form more stable conjugates than synthetic polyamines. Modelling showed that polyamines are located at the surface of PAMAM with the free binding energy of -3.56 (spermine), -3.88 (spermidine) and -3.13 kcal/mol (BE-333), indicating spontaneous polyamine-polymer interaction at room temperature.


Assuntos
Poliaminas Biogênicas/química , Dendrímeros/química , Nanopartículas/química , Nylons/química , Poliaminas/química , Ligações de Hidrogênio , Poliaminas/síntese química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Espermidina/química , Espermina/análogos & derivados , Espermina/química , Eletricidade Estática , Termodinâmica
11.
Sud Med Ekspert ; 58(6): 49-52, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26856062

RESUMO

This review of the literature presents the results of analysis of the publications concerning the prospects of the investigations of ptomaines including their influence on the results of determination of toxic substances present in the putrescent cadaveric tissues and on the persistence of analytes in the biological materials. Special emphasis is laid on the peculiarities of investigation of ptomaines and the necessity of the further development of the methods for the detection, isolation, and identification of toxicants in the putrescent and exhumed biological objects bearing in mind that such studies are not infrequently provide the sole opportunity to prove intoxication with certain substances.


Assuntos
Poliaminas Biogênicas , Poliaminas Biogênicas/análise , Poliaminas Biogênicas/biossíntese , Poliaminas Biogênicas/química , Toxicologia Forense/métodos , Humanos , Mudanças Depois da Morte
12.
Food Chem ; 173: 80-5, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25465997

RESUMO

The objective of this study was to monitor the post-partum variation of polyamine content, in ovine and caprine milk, from indigenous Greek breeds. Twenty samples of ewe and 20 samples of goat colostrum and milk were collected at the 1st, 2nd, 3rd, 4th, 5th and 15th day post-partum. Putrescine, spermidine and spermine were measured as dansylated derivatives by high-performance liquid chromatography. Putrescine was the least concentrated of these substances in both milk types. Spermidine was the prevailing polyamine in caprine samples, reaching levels up to 4.41 µmol/l on the 3rd day post-partum. In ovine milk, the profile of the mean concentrations showed greater levels of spermine than spermidine, except for the 5th day post-partum. These data suggest that goat colostrum and ewe milk (15th day) could be considered as good natural sources for these bioactive growth factors, and may become useful raw materials for designing tailored dairy products for specific population groups.


Assuntos
Poliaminas Biogênicas/química , Colostro/química , Leite/química , Animais , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Cabras , Gravidez , Putrescina/análise , Ovinos , Espermidina/análise , Espermina/análise
13.
Mar Biotechnol (NY) ; 16(4): 465-74, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24493382

RESUMO

Bacteria, including cyanobacteria, as well as some fungi, are known to deposit calcium carbonate (CaCO(3)) extracellularly in calcium-containing artificial medium. Despite extensive investigation, the mechanisms involved in extracellular formation of CaCO(3) by bacteria have remained unclear. The ability of synthetic amines to remove carbon dioxide (CO(2)) from natural gas led us to examine the role of biogenic polyamines in CaCO(3) deposition by bacteria. Here, we demonstrated that biogenic polyamines such as putrescine, spermidine, and spermine were able to react with atmospheric CO(2) and the resultant carbamate anion was characterized by using nuclear magnetic resonance (NMR) analysis. Biogenic polyamines accelerated the formation of CaCO(3), and we artificially synthesized the dumbbell-shaped calcites, which had the same form as observed with bacterial CaCO3 precipitates, under nonbacterial conditions by using polyamines. The reaction rate of calcification increased with temperature with an optimum of around 40 °C. Our observation suggests a novel scheme for CO(2) dissipation that could be a potential tool in reducing atmospheric CO(2) levels and, therefore, global warming.


Assuntos
Poliaminas Biogênicas/química , Poliaminas Biogênicas/metabolismo , Carbonato de Cálcio/metabolismo , Dióxido de Carbono/química , Dióxido de Carbono/isolamento & purificação , Líquido Extracelular/química , Líquido Extracelular/metabolismo , Bactérias Gram-Negativas/metabolismo
14.
PLoS One ; 8(7): e70510, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23894663

RESUMO

BACKGROUND: The thermodynamics of the base pair specificity of the binding of the polyamines spermine, spermidine, putrescine, and cadaverine with three genomic DNAs Clostridium perfringens, 27% GC, Escherichia coli, 50% GC and Micrococcus lysodeikticus, 72% GC have been studied using titration calorimetry and the data supplemented with melting studies, ethidium displacement and circular dichroism spectroscopy results. METHODOLOGY/PRINCIPAL FINDINGS: Isothermal titration calorimetry, differential scanning calorimetry, optical melting studies, ethidium displacement, circular dichroism spectroscopy are the various techniques employed to characterize the interaction of four polyamines, spermine, spermidine, putersine and cadaverine with the DNAs. Polyamines bound stronger with AT rich DNA compared to the GC rich DNA and the binding varied depending on the charge on the polyamine as spermine>spermidine >putrescine>cadaverine. Thermodynamics of the interaction revealed that the binding was entropy driven with small enthalpy contribution. The binding was influenced by salt concentration suggesting the contribution from electrostatic forces to the Gibbs energy of binding to be the dominant contributor. Each system studied exhibited enthalpy-entropy compensation. The negative heat capacity changes suggested a role for hydrophobic interactions which may arise due to the non polar interactions between DNA and polyamines. CONCLUSION/SIGNIFICANCE: From a thermodynamic analysis, the AT base specificity of polyamines to DNAs has been elucidated for the first time and supplemented by structural studies.


Assuntos
Poliaminas Biogênicas/química , DNA/química , Conformação de Ácido Nucleico , Sequência Rica em At , Composição de Bases , Varredura Diferencial de Calorimetria , Dicroísmo Circular , Putrescina/química , Espermidina/química , Espermina/química , Termodinâmica
15.
Biochimie ; 95(6): 1185-95, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23352964

RESUMO

The binding properties of five G-quadruplex oligonucleotides (humtel24, k-ras32, c-myc22, c-kit1 and c-kit2) with polyamines have been investigated by electrospray ionization-quadrupole time of flight mass spectrometry, circular dichroism, melting temperature, atomic force microscopy (AFM) and molecular simulation. The MS results demonstrated that the polyamines and G-quadruplex DNA can form complexes with high affinity, and one molecule of G-quadruplex DNA can combine several molecules (1-5) of polyamines. The binding affinities of the polyamines to DNA were in the order of spermine > spermidine > putrescine. After binding with polyamines, the conformations of the G-quadruplex DNA were significantly changed, and spermine can induce the configurations of k-ras32 and c-kit1 to deviate from their G-quadruplex structures at high concentrations. In the presence of K(+), the conformations of G-quadruplex DNA were stabilized, while polyamines can also induced alterations of their configurations. Melting temperature experiments suggested that the Tm of the DNA-polyamine complexes obviously increased both in the absence and presence of K(+). The AFM results indicated that polyamines can induce aggregation of G-quadruplex DNA. Above results illustrated that the polyamines bound with the phosphate backbone and the base-pairs of G-quadruplex structures. Combining with the molecular simulation, the binding mode of the G-quadruplex DNA and polyamines were discussed. The results obtained would be beneficial for understanding the biological and physiological functions of polyamines and provide useful information for development of antitumor drugs.


Assuntos
Poliaminas Biogênicas/química , Quadruplex G , Dicroísmo Circular , Microscopia de Força Atômica , Modelos Moleculares , Espectrometria de Massas por Ionização por Electrospray
16.
Anticancer Agents Med Chem ; 13(3): 414-21, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23092269

RESUMO

Some polyamine derivatives, namely the bisnaphthalimidopropyl polyamines (BNIPPs) may have potential as anticancer drugs. Indeed, previous work from some of us had shown that the ability of these molecules to bind to DNA may contribute to their cytotoxicity. However, their precise mode of action has not been fully understood. In the present work, we report for the first time the effect of the previously synthesised compounds, BNIPDaCHM and NPA, together with a new BNIP derivative (BNIP-3,4-DaDPM) in the in vitro growth of a non-small cell lung cancer cell line (NCI-H460). In addition, for the most potent compound (BNIPDaCHM), its activity as sirtuin inhibitor was investigated in vitro and further confirmed in silico. Results in the NCI-H460 cells showed that, from the compounds tested, BNIPDaCHM was the most potent (GI50 of 1.3 µM). In addition, a concentration-dependent alteration in the normal NCI-H460 cell cycle profile was observed following treatment with BNIPDaCHM as well as an increase in the sub-G1 peak (suggestive of apoptotis). This effect was further supported by Annexin V/PI staining and by analysing the expression of proteins related to apoptosis (cleaved PARP and Caspase-3) by Western blot. It was also observed that BNIPDaCHM inhibited the activity of SIRT2 in vitro, but not of SIRT1. Accordingly, this compound also caused a small increase in tubulin acetylation in NCI-H460 cells. To determine the binding potential of BNIPDaCHM on hSIRT2 and to further validate its inhibitory action, in silico docking studies were carried out, which revealed that BNIPDaCHM is composed of an entirely new SIRT2- inhibiting structural scaffold. In conclusion, this study indicates that BNIP derivatives with a novel structural backbone, such as BNIPDaCHM, may have potential as building blocks for novel antitumour agents which might selectively bind to hSIRT-2.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Poliaminas Biogênicas/farmacologia , Cicloexilaminas/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Naftalimidas/farmacologia , Quinolonas/farmacologia , Acetilação , Antineoplásicos/síntese química , Antineoplásicos/química , Poliaminas Biogênicas/síntese química , Poliaminas Biogênicas/química , Caspase 3/genética , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cicloexilaminas/síntese química , Cicloexilaminas/química , Relação Dose-Resposta a Droga , Humanos , Simulação de Acoplamento Molecular , Naftalimidas/síntese química , Naftalimidas/química , Inibidores de Poli(ADP-Ribose) Polimerases , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Quinolonas/síntese química , Quinolonas/química , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/genética , Sirtuína 1/metabolismo , Sirtuína 2/antagonistas & inibidores , Sirtuína 2/genética , Sirtuína 2/metabolismo , Relação Estrutura-Atividade , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo
17.
PLoS One ; 7(4): e36087, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22558341

RESUMO

Biogenic polyamines are essential for cell growth and differentiation, while polyamine analogues exert antitumor activity in multiple experimental model systems, including breast and lung cancer. Dendrimers are widely used for drug delivery in vitro and in vivo. We report the bindings of biogenic polyamines, spermine (spm), and spermidine (spmd), and their synthetic analogues, 3,7,11,15-tetrazaheptadecane.4HCl (BE-333) and 3,7,11,15,19-pentazahenicosane.5HCl (BE-3333) to dendrimers of different compositions, mPEG-PAMAM (G3), mPEG-PAMAM (G4) and PAMAM (G4). FTIR and UV-visible spectroscopic methods as well as molecular modeling were used to analyze polyamine binding mode, the binding constant and the effects of polyamine complexation on dendrimer stability and conformation. Structural analysis showed that polyamines bound dendrimers through both hydrophobic and hydrophilic contacts with overall binding constants of K(spm-mPEG-G3) = 7.6 × 10(4) M(-1), K(spm-mPEG-PAMAM-G4) = 4.6 × 10(4) M(-1), K(spm-PAMAM-G4) = 6.6 × 10(4) M(-1), K(spmd-mPEG-G3) = 1.0 × 10(5) M(-1), K(spmd-mPEG-PAMAM-G4) = 5.5 × 10(4) M(-1), K(spmd-PAMAM-G4) = 9.2 × 10(4) M(-1), K(BE-333-mPEG-G3) = 4.2 × 10(4) M(-1), K(Be-333-mPEG-PAMAM-G4) = 3.2 × 10(4) M(-1), K(BE-333-PAMAM-G4) = 3.6 × 10(4) M(-1), K(BE-3333-mPEG-G3) = 2.2 × 10(4) M(-1), K(Be-3333-mPEG-PAMAM-G4) = 2.4 × 10(4) M(-1), K(BE-3333-PAMAM-G4) = 2.3 × 10(4) M(-1). Biogenic polyamines showed stronger affinity toward dendrimers than those of synthetic polyamines, while weaker interaction was observed as polyamine cationic charges increased. The free binding energies calculated from docking studies were: -3.2 (spermine), -3.5 (spermidine) and -3.03 (BE-3333) kcal/mol, with the following order of binding affinity: spermidine-PAMAM-G-4>spermine-PAMMAM-G4>BE-3333-PAMAM-G4 consistent with spectroscopic data. Our results suggest that dendrimers can act as carrier vehicles for delivering antitumor polyamine analogues to target tissues.


Assuntos
Poliaminas Biogênicas/metabolismo , Dendrímeros/metabolismo , Poliaminas Biogênicas/química , Cátions , Dendrímeros/química , Interações Hidrofóbicas e Hidrofílicas , Cinética , Modelos Moleculares , Nylons/química , Nylons/metabolismo , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
18.
Mol Ther ; 20(1): 91-100, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21988874

RESUMO

We have designed a series of versatile lipopolyamines which are amenable to chemical modification for in vivo delivery of small interfering RNA (siRNA). This report focuses on one such lipopolyamine (Staramine), its functionalized derivatives and the lipid nanocomplexes it forms with siRNA. Intravenous (i.v.) administration of Staramine/siRNA nanocomplexes modified with methoxypolyethylene glycol (mPEG) provides safe and effective delivery of siRNA and significant target gene knockdown in the lungs of normal mice, with much lower knockdown in liver, spleen, and kidney. Although siRNA delivered via Staramine is initially distributed across all these organs, the observed clearance rate from the lung tissue is considerably slower than in other tissues resulting in prolonged siRNA accumulation on the timescale of RNA interference (RNAi)-mediated transcript depletion. Complete blood count (CBC) analysis, serum chemistry analysis, and histopathology results are all consistent with minimal toxicity. An in vivo screen of mPEG modified Staramine nanocomplexes-containing siRNAs targeting lung cell-specific marker proteins reveal exclusive transfection of endothelial cells. Safe and effective delivery of siRNA to the lung with chemically versatile lipopolyamine systems provides opportunities for investigation of pulmonary cell function in vivo as well as potential treatments of pulmonary disease with RNAi-based therapeutics.


Assuntos
Poliaminas Biogênicas/química , Pulmão/metabolismo , RNA Interferente Pequeno/administração & dosagem , Animais , Poliaminas Biogênicas/síntese química , Poliaminas Biogênicas/metabolismo , Contagem de Células Sanguíneas , Feminino , Inativação Gênica , Injeções Intravenosas , Pulmão/patologia , Camundongos , Camundongos Endogâmicos ICR , Camundongos Transgênicos , Nanoconjugados/administração & dosagem , Nanoconjugados/efeitos adversos , Nanoconjugados/química , Polietilenoglicóis/química , RNA Interferente Pequeno/síntese química , RNA Interferente Pequeno/metabolismo , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/metabolismo , Transfecção
19.
Int J Biol Macromol ; 49(2): 201-9, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21569792

RESUMO

The bindings of biogenic polyamines spermine (spm), spermidine (spmd) and synthetic polyamines 3,7,11,15-tetrazaheptadecane·4HCl (BE-333) and 3,7,11,15,19-pentazahenicosane·5HCl (BE-3333) with ß-lactoglobulin (ß-LG) were determined in aqueous solution. FTIR, UV-vis, CD and fluorescence spectroscopic methods as well as molecular modeling were used to determine the polyamine binding sites and the effect of polyamine complexation on protein stability and secondary structure. Structural analysis showed that polyamines bind ß-LG via both hydrophilic and hydrophobic contacts. Stronger polyamine-protein complexes formed with synthetic polyamines than biogenic polyamines, with overall binding constants of K(spm-ß-LG)=3.2(±0.6)×10(4) M(-1), K(spmd-ß-LG)=1.8(±0.5)×10(4) M(-1), K(BE-333-ß-LG)=5.8(±0.3)×10(4) M(-1) and K(BE-3333-ß-LG)=6.2(±0.05)×10(4) M(-1). Molecular modeling showed the participation of several amino acids in the polyamine complexes with the following order of polyamine-protein binding affinity: BE-3333>BE-333>spermine>spermidine, which correlates with their positively charged amino group content. Alteration of protein conformation was observed with a reduction of ß-sheet from 57% (free protein) to 55-51%, and a major increase of turn structure from 13% (free protein) to ∼21% in the polyamine-ß-LG complexes, indicating a partial protein unfolding.


Assuntos
Poliaminas Biogênicas/metabolismo , Lactoglobulinas/metabolismo , Sítios de Ligação , Poliaminas Biogênicas/síntese química , Poliaminas Biogênicas/química , Interações Hidrofóbicas e Hidrofílicas , Lactoglobulinas/química , Modelos Moleculares , Ligação Proteica , Estabilidade Proteica , Estrutura Secundária de Proteína , Espermidina/química , Espermidina/metabolismo
20.
RNA ; 16(10): 1968-79, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20729276

RESUMO

Biogenic polyamines are found to modulate protein synthesis at different levels. This effect may be explained by the ability of polyamines to bind and influence the secondary structure of tRNA, mRNA, and rRNA. We report the interaction between tRNA and the three biogenic polyamines putrescine, spermidine, spermine, and cobalt(III)hexamine at physiological conditions, using FTIR spectroscopy, capillary electrophoresis, and molecular modeling. The results indicated that tRNA was stabilized at low biogenic polyamine concentration, as a consequence of polyamine interaction with the backbone phosphate group. The main tRNA reactive sites for biogenic polyamine at low concentration were guanine-N7/O6, uracil-O2/O4, adenine-N3, and 2'OH of the ribose. At high polyamine concentration, the interaction involves guanine-N7/O6, adenine-N7, uracil-O2 reactive sites, and the backbone phosphate group. The participation of the polycation primary amino group, in the interaction and the presence of the hydrophobic contact, are also shown. The binding affinity of biogenic polyamine to tRNA molecule was in the order of spermine > spermidine > putrescine with K(Spm) = 8.7 × 10(5) M(-1), K(Spd) = 6.1 × 10(5) M(-1), and K(Put) = 1.0 × 10(5) M(-1), which correlates with their positively charged amino group content. Hill analysis showed positive cooperativity for the biogenic polyamines and negative cooperativity for cobalt-hexamine. Cobalt(III)hexamine contains high- and low-affinity sites in tRNA with K(1) = 3.2 × 10(5) M(-1) and K(2) = 1.7 × 10(5) M(-1), that have been attributed to the interactions with guanine-N7 sites and the backbone PO(2) group, respectively. This mechanism of tRNA binding could explain the condensation phenomenon observed at high Co(III) content, as previously shown in the Co(III)-DNA complexes.


Assuntos
Poliaminas Biogênicas/metabolismo , RNA de Transferência/metabolismo , Sítios de Ligação , Poliaminas Biogênicas/química , Cobalto/metabolismo , Eletroforese Capilar , Cinética , Modelos Moleculares , Conformação de Ácido Nucleico , Putrescina/metabolismo , Estabilidade de RNA , RNA Fúngico/química , RNA Fúngico/metabolismo , RNA de Transferência/química , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Espermidina/metabolismo , Espermina/metabolismo
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