RESUMEN
The pathogenesis of multiple sclerosis (MS), a chronic disease of the CNS, includes autoimmune and neurodegenerative components. In most cases, patients develop relapsing-remitting MS (RRMS), while 10-15% of patients develop primary progressive MS (PPMS), which differs from RRMS in the mechanisms of the pathological process, some demographic, and some clinical characteristics. These differences may be explained by the epigenetic regulation of gene expression in PPMS including DNA methylation as one of the key epigenetic processes. The features of DNA methylation in various cell populations in PPMS patients remain understudied. The goal of this study is to identify differentially methylated CpG sites (DMSs) of the genome of CD4+ T lymphocytes, which characterize PPMS. The study included eight treatment-naive PPMS patients and eight healthy controls. Genome-wide analysis of DNA methylation of CD4+ T lymphocytes was performed using high-density DNA microarrays. We have identified 108 DMSs, which distinguish PPMS patients from healthy controls. In PPMS patients 81% of the DMSs are hypermethylated. More than a half of the identified DMSs are located in known genes in CpG islands and adjacent regions, which indicates a high functional significance of these DMSs in PPMS development. Analysis of the overrepresentation of DMS-containing genes in the main biological processes demonstrates their involvement in the regulation of cell adhesion to the extracellular matrix and the development of the immune response, i.e., antigen processing and presentation, and development of the immune system. Genome-wide analysis of DNA methylation in CD4+ T lymphocytes of PPMS patients indicates the involvement of this epigenetic process in the immunopathogenesis of the disease. These results may help better understand the pathogenesis of this severe form of MS.
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Esclerosis Múltiple Crónica Progresiva , Esclerosis Múltiple , Linfocitos T CD4-Positivos/metabolismo , Metilación de ADN , Epigénesis Genética , Humanos , Esclerosis Múltiple/genética , Esclerosis Múltiple Crónica Progresiva/genéticaRESUMEN
We developed a model of blood hyperviscosity avoiding extreme impact on the blood. The model shows reproducibility in rat blood under common storage conditions (4±1°C; stabilization with citrate-phosphate-glucose additive solution). Storage of rat blood under these condition leads to impairment of its rheological properties, which manifested in an increase in blood viscosity in a wide range of shear rates (3-300 sec-1). An increase in blood viscosity appeared the first day of storage and reached a maximum on the third day. During further 11-day storage, the blood viscosity did not change significantly. A hybrid macromolecular compound O-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)-(1â6)-α-D-glucan improved the hemorheological properties during storage. The most pronounced effect was observed on the third day of storage and manifested in a decrease in blood viscosity in the range of shear rates of 50-300 sec-1. Thus, storage of rat blood with citrate-phosphate-glucose additive solution for 3 days at 4±1°C reproduces the phenomenon of blood hyperviscosity; this model can be used to screen agents with hemorheological activity.
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Viscosidad Sanguínea , Animales , Ratas , Reproducibilidad de los Resultados , ReologíaRESUMEN
Glaucoma is the leading cause of irreversible blindness in all countries and is expected to increase in patients with this pathology in the coming years. Currently, the development of the disease is associated with a change in the interleukin profile of the lacrimal fluid, but the diagnostic significance of interleukins has not been sufficiently studied. PURPOSE: To determine the diagnostic significance of interleukins at the local level to improve the diagnosis and prognosis of glaucoma. MATERIAL AND METHODS: The study examined the content of interleukins in the lacrimal fluid of 109 patients with stage II glaucoma and 52 healthy individuals by sandwich-variant of enzyme-linked immunosorbent assay (ELISA) with calculation of the information content of immune parameters. RESULTS: The study has established high diagnostic significance for the verification of glaucoma IL-2, IL-17, IL-8, which is proposed to be used in laboratory diagnosis and prognosis of the disease. CONCLUSION: The created regression model provides high-accuracy prediction of the course of glaucoma progression with increasing IL-2, IL-17, IL-8.
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Glaucoma de Ángulo Abierto , Glaucoma , Citocinas , Humanos , Interleucinas , LágrimasRESUMEN
Multiple sclerosis is a chronic disease of the central nervous system, combining in its pathogenesis both autoimmune and neurodegenerative components, and is characterized by a highly heterogeneous clinical phenotype. Genetic susceptibility to the development of the most common relapsing-remitting course of the disease is extensively studied, while the genetic architecture of the aggressive primary progressive course of multiple sclerosis remains poorly understood. We analyzed the association of polymorphic variants in miRNA genes MIR146A, MIR196A2, and MIR499A with the risk of primary progressive multiple sclerosis one by one and in biallelic combinations with variants of immune-related genes; the analysis was performed in comparison with healthy individuals and with relapsing-remitting multiple sclerosis patients. The allele MIR196A2*C was useful in discriminating between two main courses of multiple sclerosis, one by one and in combination with alleles of the IFNAR2, IL7RA, IL6, PVT1, CD86, CCL5, and PSMB9 genes. The data presented in the current work may be used for the construction of a biomarker panel, to differentiate primary progressive and relapsing-remitting courses of multiple sclerosis on the initial stages of the disease.
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Predisposición Genética a la Enfermedad , MicroARNs/genética , Esclerosis Múltiple Crónica Progresiva/genética , Polimorfismo Genético , Alelos , Humanos , Factores de RiesgoRESUMEN
The effect of chitosan- and vanillin-based immune modulators on the development of the phytopathogen Cochliobolus sativus (S. Ito & Kurib.) Drechsler ex Dastur, which induces dark-brown blotch (helminthosporiosis) in wheat, has been studied. It was shown that treatment with these substances led to a decreased injured area in leaves and an increase in the biotrophic period of pathogen development. It was found that vanillin-modified chitosan effectively provided wheat resistance to hemibiotrophic pathogen C. sativus. Changes in leaf peroxidase activity correlated with the manifestation of disease symptoms.
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Ascomicetos/crecimiento & desarrollo , Benzaldehídos , Quitosano , Resistencia a la Enfermedad/efectos de los fármacos , Factores Inmunológicos , Enfermedades de las Plantas/microbiología , Triticum , Ascomicetos/inmunología , Benzaldehídos/química , Benzaldehídos/farmacología , Quitosano/química , Quitosano/farmacología , Factores Inmunológicos/química , Factores Inmunológicos/farmacología , Enfermedades de las Plantas/inmunología , Triticum/crecimiento & desarrollo , Triticum/microbiologíaRESUMEN
The purpose: The influence of high-fat diet (HFD) on trace elements status, adipokine level, and markers of carbohydrate and lipid metabolism in weanling Wistar rats was investigated. Methods: A total of 20 male 1-months-old Wistar rats divided into two equal groups were used in the present study. The first group of animals obtained a standard diet (STD), whereas animals from the second group (NAFLD) were maintained on high-fat diet containing 10 and 31.6% of total calories from fat, respectively, during 1 month. Fat diet (HFD). Trace element status (using inductively coupled plasma mass spectrometry), serum levels of insulin, adiponectin, and leptin (using enzyme-linked immunosorbent assay), total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), glucose (spectrophotometrically), apolipoprotein A1 (ApoA1) and B (ApoB) (using immunoturbidimetric method) were assessed. Results: It was shown that 1-month HFD feeding resulted in significant increase of EDAT, RPAT, total adipose tissue mass, and adipocyte area. HFD-fed animals were also characterized by a significant increase in circulating leptin levels and leptin-to-adiponectin ratio as compared to the control ones. No significant HFD-related difference in serum lipid spectrum, adiponectin, apolipoproteins, glucose, insulin, and HOMA-IR were revealed. Liver Cu, I, Mn, Se, Zn; EDAT Cr, V, Co, Cu, Fe,I, and RPAT Co, Cu, I, Cr, V, Fe, and Zn were significantly decreased in HFD-fed rats in comparison with the control group levels. Hair Co, Mn, Si, and V levels significantly exceeded the respective control values, whereas Se and I content were decreased in studied animals. At the same time, only serum Cu was significantly decreased in HFD-fed rats. Conclusion: The interplay between the impaired trace elements metabolism of HFD-fed weanling Wistar rats and disorder of adipokine balance was demonstrated. It is supposed that the altered trace elements status is primary and precedes other metabolic obesity-related disturbances.
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Grasas de la Dieta/farmacología , Lípidos/sangre , Lipoproteínas/sangre , Oligoelementos/sangre , Animales , Masculino , Ratas , Ratas WistarRESUMEN
BACKGROUND: The efficiency of long-term cryogenic storage to prevent somaclonal variations in plant cell cultures and retain their major cytogenetic and biochemical traits remains under debate. In particular, it is not clear how stress conditions associated with cryopreservation, such as low temperature, dehydration and toxic action of some cryoprotectants (DMSO in particular), affect post-storage regrowth and genetic integrity of cell samples. OBJECTIVE: We assessed growth, cytogenetic and biochemical characteristics of the peroxidase-producing strain of Medicago sativa L. cell culture recovered after 27 years of cryogenic storage as compared to the same culture before cryopreservation. MATERIALS AND METHODS: In 1984, M. sativa L. cell culture was cryopreserved using programmed freezing and 7% DMSO as a cryoprotectant. In 2011, after rewarming in a water bath at 40 degree C for 90 s, cell culture was recovered and proliferated. Viability, growth profile, mitotic index, ploidy level, peroxidase activity and cell response to hypothermia and osmotic stress were compared between the recovered and the initial cell cultures using the records available from 1984. RESULTS: Viability of alfalfa cell culture after rewarming was below 20% but it increased to 80% by the 27th subculture cycle. Recovered culture showed higher mitotic activity and increased number of haploid and diploid cells compared to the initial cell line. Both peroxidase activity and response to abiotic stress in the recovered cell culture were similar to that of the initial culture. CONCLUSION: Cryopreservation by programmed freezing was effective at retaining the main characteristics of M. sativa undifferentiated cell culture after 27 years of storage. According to available data, this is longest period of successful cryopreservation of plant cell cultures reported so far. After storage, there was no evidence that DMSO had any detrimental effect on cell viability, growth or cytogenetics.
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Criopreservación , Medicago sativa/citología , Medicago sativa/crecimiento & desarrollo , Técnicas de Cultivo de Célula , Supervivencia Celular/efectos de los fármacos , Frío , Criopreservación/métodos , Crioprotectores/farmacología , Dimetilsulfóxido/farmacología , Congelación , Medicago sativa/efectos de los fármacos , Medicago sativa/genética , Peroxidasa/metabolismo , Proteínas de Plantas/metabolismoRESUMEN
"Genetics of behavior," or "Neurogenetics," is based on the evolutionary ideas of T. Dobzhansky on brain development and behavior. It continues with the "experimental genetics of higher nervous activity" of I. Pavlov and uses a comparative approach in the study of heredity and variation in behavioral manifestations, from Protozoa to humans. The study of the classical Pavlovian conditioned reflex in mutant Drosophila helped to identify the main types of memory and their evolutionary conservatism. Long-term memory defects are caused by mutations of the same genes as in mental, retardation in humans, when signaling cascades intersecting with the cAMP-dependent pathway are damaged. The cascade of actin remodeling is also among these. The key enzyme, LIM-kinase 1, controls cognitive manifestations of the "genomic disease" Williams deletion syndrome. Its study resulted in the recognition of neuroepigenetics as an interface between the genome and environmental influences. Epigenetic factors of "variability"--DNA methylation, histone acetylation, and microRNA regulation--do not change the structure of the gene but its manifestations. Certain miRNAs have already been considered to be both biomarkers for neurodegenerative diseases and factors of the intergenerational transmission of the behaviorial properties of ancestors who experienced stress from adverse environmental influences.
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Epigénesis Genética , Epigenómica , Evolución Molecular , Enfermedades Neurodegenerativas/genética , Animales , Metilación de ADN/genética , Drosophila , Humanos , Quinasas Lim/genética , MicroARNs/genética , Transducción de Señal/genéticaRESUMEN
We have shown previously that the polymorphic structure of the limk1 gene in drosophila leads to changes in LIMK1 content and to defects in courtship behavior, sound production, and learning/memory. The results of the present study of three wild-type strains and mutant agn(ts3) with altered limk1 structure demonstrate that long-term memory is normal in Canton-S and Oregon-R but is impaired in Berlin and drastically suppressed in agn(ts3). This temperature-sensitive mutant carries the S-element from the Tc1/mariner family insertion near the dlimk1 3'-UTR and, compared to Canton-S, has a reverse pCREB distribution in adult neuromuscular junctions (NMJ) of the second dorsal imago nerve before and after learning. Moreover, only agn(ts3) demonstrates amyloid-like aggregate formation in NMJ. This suggests that this impedes pCREb transport and thereby impairs the formation of short- and long-term memory.
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Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Quinasas Lim/genética , Memoria , Unión Neuromuscular/metabolismo , Polimorfismo de Nucleótido Simple , Agregado de Proteínas , Animales , Drosophila melanogaster/metabolismo , Drosophila melanogaster/fisiologíaRESUMEN
Elucidation of molecular mechanisms of cognitive functions is one of the major achievements in neurobiology. At most, this is due to the studies on the simple nervous systems, such as the CNS in Drosophila melanogaster. Many of its functional characteristics are pretty similar to higher vertebrates. Among these are: 1) evolutionary conservation of genes and molecular systems involved in the regulation of learning acquisition and memory formation; 2) presence of highly specialized and differentiated sensory, associative and motor centers; 3) utilization of similar modes of informational coding and analysis; 4) availability of major learning forms including non-associative, as well as associative learning; 5) diversity of different memories, including short-term- and protein synthesis- dependent long-term memory; 6) presence of aminergic reinforcement systems in the brain; 7) feed-back loops of circadian clocks, current organism experience and individual organism characters affecting cognitive process per se. In this review the main attention is paid to the two mostly studied Drosophila learning forms, namely to olfactory Iearning and courtship suppression conditioning (CCS). A separate consideration is given to the impacts of kynurenins and metabolite of actin remodeling signal cascade.
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Encéfalo/fisiología , Proteínas de Drosophila/genética , Drosophila/fisiología , Memoria , Animales , Encéfalo/metabolismo , Drosophila/genética , Proteínas de Drosophila/metabolismoRESUMEN
The stability of mRNA and its translation efficacy in higher eukaryotes are influenced by the interaction of 3'-untranscribed regions (3'-UTRs) with microRNAs and RNA-binding proteins. Since Saccharomyces cerevisiae lack microRNAs, it is possible to evaluate the contribution of only 3'-UTRs' and RNA-binding proteins' interaction in post-transcriptional regulation. For this, the post-transcriptional regulation of Drosophila limk1 gene encoding for the key enzyme of actin remodeling was studied in yeast. Analysis of limkl mRNA 3'-UTRs revealed the potential sites of yeast transcriptional termination. Computer remodeling demonstrated the possibility of secondary structure formation in limkl mRNA 3'-UTRs. For an evaluation of the functional activity of Drosophila 3'-UTRs in yeast, the reporter gene PHO5 encoding for yeast acid phosphatase (AP) fused to different variants of Drosophila limk1 mRNA 3'-UTRs (513, 1075, 1554 bp) was used. Assessments of AP activity and RT-PCR demonstrated that Drosophila limkl gene 3'-UTRs were functionally active and recognized in yeast. Therefore, yeast might be used as an appropriate model system for studies of 3'-UTR's role in post-transcriptional regulation.
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Regiones no Traducidas 3' , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Quinasas Lim/metabolismo , ARN Mensajero/metabolismo , Saccharomyces cerevisiae/genética , Fosfatasa Ácida/genética , Fosfatasa Ácida/metabolismo , Animales , Proteínas de Drosophila/genética , Genes Reporteros , Quinasas Lim/genética , ARN Mensajero/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMEN
In this paper we present results of a comprehensive analysis of the effect of heat shock at different stages of ontogenesis (adult stage, development of the mushroom bodies and the central complex) on courtship behavior (latency, duration and efficacy of courtship), sound production (pulse interval, dispersion of interpulse interval, the percentage of distorted pulses, the mean duration of the pulse parcels), learning and memory formation compared with the content of isoforms LIMK1 in Drosophila melanogaster male with altered structure of the limk1 gene. The heat shock is shown to affect the behavior parameters and LIMK1 content in analyzed strains of Drosophila. The most pronounced effect of the heat shock was observed at the stage of development of the central complex (CC). Heat shock at CC and adult restores the ability of learning and memory formation in the mutant strain agn(ts3), which normally is not able to learn and form memory. Correlations between changes of content of isoforms LIMK1 and behavioral parameters due to heat shock have not been established.
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Encéfalo/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiología , Respuesta al Choque Térmico , Quinasas Lim/metabolismo , Animales , Encéfalo/crecimiento & desarrollo , Encéfalo/fisiología , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crecimiento & desarrollo , Aprendizaje , Quinasas Lim/genética , Masculino , Memoria , Cuerpos Pedunculados/crecimiento & desarrollo , Cuerpos Pedunculados/metabolismo , Cuerpos Pedunculados/fisiología , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Conducta Sexual Animal , Vocalización AnimalRESUMEN
The article covers results of study concerning disperse content of solid components of discharges from main dust- generating technologic operations in extraction and processing of mineral raw materials (pouring ore to conveyor, drying with combustion gas in fluid-bed, pouring of end product, sorting ore on riddle, drying on vibration dry and cool device, etc). Findings are that fractions under 10 and 2.5 micrometers approach 50% in general structure of dust discharges. Maximal share of low-disperse dust enters ambient air from vibraion dry and cool devices, riddles and pouring places. Exceeded reference values for acute and chronic exposure are registered on TSP and PM10 at a sanitary protection zone border and in the nearest living area points--that can forecast intolerable risks for health of population exposed and necessitate instrumental confirmation of the detected jeopardy level.
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Contaminantes Atmosféricos/normas , Polvo , Exposición a Riesgos Ambientales/normas , Industria Procesadora y de Extracción/normas , HumanosRESUMEN
Intermolecular interactions in several dimer aromatic systems were analyzed to determine how various energy contributions (electrostatic, exchange, repulsion, and polarization) change depending on the value of monomers separation. Different contributions to the intermolecular energy interactions between imidazole-imidazole and benzene-imidazole dimers are studied using the aug-cc-pVDZ basis set in the framework of ab initio Hartree-Fock and second-order Møller-Plesset perturbation theory methods. Special attention is paid to the exchange and dispersion energy binding contributions.
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Benceno/química , Imidazoles/química , TermodinámicaRESUMEN
Microorganisms in human life play a huge role: in particular, those that coexist with the host organism, inhabiting the skin, upper respiratory tract, external genitalia and especially the digestive tract. The intestinal microbiota, including bacteriome, mycobiome and virome, not only takes part in the digestion process, but also provides the synthesis of a number of vitamins. The intestinal microbiome also serves as the basis for a system of extensive bidirectional neuroendocrine pathways that connect microbiota with various regions of the central nervous system, the hypothalamic-pituitary-adrenal system, and the peripheral parts of the autonomic nervous system. This system of connections has got the name of gut-brain axis and has attracted close attention of scientists over the past two decades, since a targeted impact on the intestinal flora is potentially capable of changing the nature of nervous system regulatory influences on the whole body. It is especially important to study patterns of functioning of the gut-brain axis in patients with the nervous system pathology, namely neurodegenerative and demyelinating diseases. Methods for their treatment continue to improve, and perhaps the correction of the gut microbiotic composition will serve as an additional therapeutic approach. The review article describes current views on the role of the intestinal microbiota, provides the latest data on the composition of bacteriome, mycobiome, and virome in patients with relapsing-remitting multiple sclerosis.
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Microbioma Gastrointestinal , Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Humanos , Microbioma Gastrointestinal/fisiología , Encéfalo/fisiología , Esclerosis Múltiple Recurrente-Remitente/metabolismo , Esclerosis Múltiple/metabolismo , Sistema Nervioso CentralRESUMEN
The signal pathway of actin remodeling, including LIM-kinase 1 (LIMK1) and its substrate cofilin, regulates multiple processes in neurons of vertebrates and invertebrates. Drosophila melanogaster is widely used as a model object for studying mechanisms of memory formation, storage, retrieval and forgetting. Previously, active forgetting in Drosophila was investigated in the standard Pavlovian olfactory conditioning paradigm. The role of specific dopaminergic neurons (DAN) and components of the actin remodeling pathway in different forms of forgetting was shown. In our research, we investigated the role of LIMK1 in Drosophila memory and forgetting in the conditioned courtship suppression paradigm (CCSP). In the Drosophila brain, LIMK1 and p-cofilin levels appeared to be low in specific neuropil structures, including the mushroom body (MB) lobes and the central complex. At the same time, LIMK1 was observed in cell bodies, such as DAN clusters regulating memory formation in CCSP. We applied GAL4 × UAS binary system to induce limk1 RNA interference in different types of neurons. The hybrid strain with limk1 interference in MB lobes and glia showed an increase in 3-h short-term memory (STM), without significant effects on long-term memory. limk1 interference in cholinergic neurons (CHN) impaired STM, while its interference in DAN and serotoninergic neurons (SRN) also dramatically impaired the flies' learning ability. By contrast, limk1 interference in fruitless neurons (FRN) resulted in increased 15-60 min STM, indicating a possible LIMK1 role in active forgetting. Males with limk1 interference in CHN and FRN also showed the opposite trends of courtship song parameters changes. Thus, LIMK1 effects on the Drosophila male memory and courtship song appeared to depend on the neuronal type or brain structure.
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OBJECTIVE: To evaluate the severity and frequency of infusion reactions (IR) in patients with highly active relapsing-remitting multiple sclerosis (MS) In Russian population receiving alemtuzumab therapy. MATERIAL AND METHODS: In retrospective study, we analyzed data from 50 patients with highly active relapsing-remitting multiple sclerosis (MS) from six Regional MS Centers in the Russian Federation who received two courses of alemtuzumab between 2018 and 2022. RESULTS: Among all IRs, the most frequently reported were hives-like rashes, which were registered in 27 people, mostly of mild severity (70.6%). Headaches were the second most common IR, observed in 17 patients (34%). When comparing the group of patients who underwent music therapy (MT) with those who received alemtuzumab therapy without MT, no statistically significant difference was found in the frequency and severity of IRs. CONCLUSION: All patients experienced IRs of varying degrees of severity. A decrease in the score on the EDSS disability scale was noted. MT did not affect the occurrence or severity of IRs.
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Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Humanos , Alemtuzumab/efectos adversos , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Estudios Retrospectivos , Federación de RusiaRESUMEN
Protein-ligand docking and molecular dynamics studies have shown that the key event initiated by 3':5'-AMP binding to the A- and B-domains of protein kinase A Iα regulatory subunit is formation of a hydrogen bond between 3':5'-AMP and A202(A326) (the residue in parentheses being from the B-domain). The A202(A326) amide group movement associated with the bond formation leads to reorganization of the phosphate binding cassette (PBC) (the short 3(10)-helix becomes the long α-helix). This process results in L203(L327) displacement and finally causes hinge (B-helix) rotation. The L203(L327) displacement and packing into the hydrophobic pocket formed by the PBC and ß2ß3-loop also depends on the ß2ß3-loop conformation. The correct conformation is maintained by R, I, E, but not K at position 209(333) of the A- and B-domains. So, the R209K and R333K mutants have problems with reaching B-conformation. The apo-form of the 3':5'-AMP-binding domain also undergoes transition from H- to B-conformation. In this case, the movement of A202(A326) amide group seems to be a result of reorganization of the PBC into a more stable α-helix.
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Subunidad RIalfa de la Proteína Quinasa Dependiente de AMP Cíclico/química , AMP Cíclico/análogos & derivados , Sitios de Unión , AMP Cíclico/metabolismo , Subunidad RIalfa de la Proteína Quinasa Dependiente de AMP Cíclico/genética , Subunidad RIalfa de la Proteína Quinasa Dependiente de AMP Cíclico/metabolismo , Ligandos , Simulación de Dinámica Molecular , Mutación , Fosfatos/química , Fosfatos/metabolismo , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , TermodinámicaRESUMEN
Protein-ligand docking and ab initio calculations have shown that the 3':5'-AMP phosphorothioate analog (Rp-3':5'-AMPS) blocks the A326 amide group displacement typical of transition from the H- to B-conformation within the B-domain of protein kinase A Iα R-subunit. This behavior of Rp-3':5'-AMPS leads to the inhibition of initial stages of hydrophobic relay operation. In accordance with the proposed hypothesis, Rp-3':5'-AMPS similarly to 3':5'-AMP forms a hydrogen bond with the amide group of A326; however, the properties of this bond together with the position of the sulfur atom prevent the movement of A326. Finally, the Rp-3':5'-AMPS-bound domain appears to be locked in the H-conformation, which is in agreement with the X-ray data.
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Subunidad RIalfa de la Proteína Quinasa Dependiente de AMP Cíclico/química , AMP Cíclico/análogos & derivados , Sitios de Unión , Simulación por Computador , AMP Cíclico/metabolismo , Subunidad RIalfa de la Proteína Quinasa Dependiente de AMP Cíclico/metabolismo , Enlace de Hidrógeno , Estructura Terciaria de Proteína , Teoría CuánticaRESUMEN
We investigated the effects of desiccation, rehydration and cryopreservation on the viability of seeds of a wild mountain species and seven clones of Salix caprea L. Seeds responded differently to all treatments depending on clone, seed initial moisture content (MC) and seed vigour. Fresh seeds of two randomly selected clones tolerated desiccation to MC 8.5-9.6 % FW (0.09-0.11 g water per g dry mass. g/gdw) without any noticeable loss in viability and were successfully cryopreserved at MCs ranging from 8.5 to 23.4 % (0.09-0.30 g/gdw). Storage at 5 degree C for approximately 10 weeks significantly reduced the viability of seed lots of a wild species and of three S. caprea clones, whilst viability of seeds of four other clones remained unaffected. Since all clones tested were genetically derived from one tree, this variation is unlikely to be of maternal origin. Most probably paternal x environmental factors have influenced seed behavior during desiccation and storage. As viability decreased due to partial ageing, seeds became more susceptible to desiccation stress. When seeds of three clones were cryopreserved, the hydration window for survival was wider for highly vigorous seeds (c. 0.05-0.28 g/gdw) than for seeds with intermediate vigour (c. 0.10-0.24 g/gdw) and low vigour (c. 0.20-0.37 g/gdw). Rehydration to MC above 0.15 g/gdw improved germination of low vigour seeds, both in controls and after cryopreservation. In contrast, cryopreservation of high vigour seeds rehydrated to MCs above 0.11 g/gdw resulted in a sharp decrease in normal seedling production. Whilst no effect of cryogenic temperature on germination and normal seedling production was observed when seeds of seven clones were cryopreserved within their hydration windows, the results indicate the need to account for seed lot vigour when designing cryopreservation protocols.