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1.
Surg Endosc ; 38(2): 529-539, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38062181

RESUMO

BACKGROUND: Endometriosis is a chronic condition affecting 6-10% of women of reproductive age, with endometriosis-related pain and infertility being the leading symptoms. Currently, the gold standard treatment approach to surgery is conventional laparoscopy (CL); however, the increasing availability of robot-assisted surgery is projected as a competitor of CL. This study aimed to compare the perioperative outcomes of robot-assisted laparoscopy (RAL) and CL in endometriosis surgery. OBJECTIVES: We aimed to compare the effectiveness and safety of these two procedures. METHODS: A systematic search was conducted in three medical databases. Studies investigating different perioperative outcomes of endometriosis-related surgeries were included. Results are presented as odds ratios (OR) or mean differences (MD) with 95% confidence intervals (CI). RESULTS: Our search yielded 2,014 records, of which 13 were eligible for data extraction. No significant differences were detected between the CL and RAL groups in terms of intraoperative complications (OR = 1.07, CI 0.43-2.63), postoperative complications (OR = 1.3, CI 0.73-2.32), number of conversions to open surgery (OR = 1.34, CI 0.76-2.37), length of hospital stays (MD = 0.12, CI 0.33-0.57), blood loss (MD = 16.73, CI 4.18-37.63) or number of rehospitalizations (OR = 0.95, CI 0.13-6.75). In terms of operative times (MD = 28.09 min, CI 11.59-44.59) and operating room times (MD = 51.39 min, CI 15.07-87.72;), the RAL technique remained inferior. CONCLUSION: RAL does not have statistically demonstrable advantages over CL in terms of perioperative outcomes for endometriosis-related surgery.


Assuntos
Endometriose , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Robótica , Feminino , Humanos , Endometriose/cirurgia , Procedimentos Cirúrgicos Robóticos/métodos , Laparoscopia/métodos , Complicações Intraoperatórias/cirurgia
2.
Org Biomol Chem ; 21(44): 8829-8836, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37917021

RESUMO

An asymmetric cyanine-type fluorescent dye was designed and synthesized via a versatile, multi-step process, aiming to conjugate with an Her2+ receptor specific antibody by an azide-alkyne click reaction. The aromaticity and the excitation and relaxation energetics of the fluorophore were characterized by computational methods. The synthesized dye exhibited excellent fluorescence properties for confocal microscopy, offering efficient applicability in in vitro imaging due to its merits such as a high molar absorption coefficient (36 816 M-1 cm-1), excellent brightness, optimal wavelength (627 nm), larger Stokes shift (26 nm) and appropriate photostability compared to cyanines. The conjugated cyanine-trastuzumab was constructed via an effective, metal-free, strain-promoted azide-alkyne click reaction leading to a regulated number of dyes being conjugated. This novel cyanine-labelled antibody was successfully applied for in vitro confocal imaging and flow cytometry of Her2+ tumor cells.


Assuntos
Azidas , Corantes Fluorescentes , Carbocianinas , Anticorpos , Alcinos , Microscopia Confocal
3.
ACS Omega ; 8(25): 22836-22843, 2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37396252

RESUMO

A novel family of julolidine-containing fluorescent rhodols equipped with a wide variety of substituents was synthesized in a versatile two-step process. The prepared compounds were fully characterized and exhibited excellent fluorescence properties for microscopy imaging. The best candidate was conjugated to the therapeutic antibody trastuzumab through a copper-free strain-promoted azide-alkyne click reaction. The rhodol-labeled antibody was successfully applied for in vitro confocal and two-photon microscopy imaging of Her2+ cells.

4.
Artigo em Inglês | MEDLINE | ID: mdl-35953148

RESUMO

OBJECTIVE: Gibraltar is a unique densely populated multicultural British Overseas Territory for which no population data on disorders of gut-brain interaction have existed.We aimed to provide the first-ever assessment of prevalence of irritable bowel syndrome and functional dyspepsia in Gibraltar in relation to their diagnostic recognition and healthcare burden. DESIGN: An internet survey was carried out in Gibraltar in 2019-2020. The study survey included demographic questions, the Rome IV diagnostic questions for functional dyspepsia and irritable bowel syndrome, relevant medical history, previous surgeries, medication use, healthcare visit frequency and a quality-of-life questionnaire. RESULTS: 888 individuals (3.5% of all Gibraltar adults) completed the survey anonymously. Irritable bowel syndrome prevalence was 5.2% (95% CI 3.7% to 6.6%). Functional dyspepsia prevalence was 9.9% (95% CI 7.9% to 11.9%). The two conditions overlapped substantially. Women had higher mean prevalence than men of both disorders. People meeting criteria for either or both disorders were prone to surgeries, had more frequent healthcare visits, higher medication use and lower quality-of-life scores compared with people without these disorders. Diagnostic recognition by healthcare providers was low, leaving 58.3% of irritable bowel syndrome and 96.9% of functional dyspepsia individuals undiagnosed. CONCLUSION: This first-ever population-based study of Rome IV defined irritable bowel syndrome and functional dyspepsia in Gibraltar indicates that the prevalence rates of these disorders are similar to the recently reported data for the UK and Spain, but they remain poorly recognised despite substantially affecting the quality of life of individuals who have them in the Gibraltar community.


Assuntos
Dispepsia , Síndrome do Intestino Irritável , Adulto , Atenção à Saúde , Dispepsia/epidemiologia , Feminino , Gibraltar , Humanos , Síndrome do Intestino Irritável/diagnóstico , Síndrome do Intestino Irritável/epidemiologia , Masculino , Prevalência , Qualidade de Vida , Cidade de Roma
5.
J Physiol ; 599(22): 4955-4971, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34587656

RESUMO

Cystic fibrosis transmembrane conductance regulator (CFTR) has an essential role in maintaining pancreatic ductal function. Impaired CFTR function can trigger acute pancreatitis (AP) and exacerbate disease severity. We aimed to investigate the localization and expression of CFTR during AP, and determined the effects of a CFTR corrector (VX-661) and potentiator (VX-770) on disease severity. AP was induced in FVB/n mice by 6-10 hourly intraperitoneal injections of 50 µg/kg cerulein. Some mice were pre-treated with five to six daily injections of 2 mg/kg VX-661 + VX-770. Control animals were administered physiological saline instead of cerulein and dimethyl sulfoxide instead of VX compounds. AP severity was determined by measuring laboratory and histological parameters; CFTR and CK19 expression was measured. Activity of ion transporters was followed by intracellular pH or fluid secretion measurement of isolated pancreatic intra-/interlobular ducts. Cerulein-induced AP severity was greatest between 12 and 24 h. CFTR mRNA expression was significantly increased 24 h after AP induction. Immunohistochemistry demonstrated disturbed staining morphology of CFTR and CK19 proteins in AP. Mislocalization of CFTR protein was observed from 6 h, while expression increased at 24 h compared to control. Ductal HCO3- transport activity was significantly increased 6 h after AP induction. AP mice pre-treatment with VX-661 + VX-770 significantly reduced the extent of tissue damage by about 20-30%, but other parameters were unchanged. Interestingly, VX-661 + VX-770 in vitro administration significantly increased the fluid secretion of ducts derived from AP animals. This study described the course of the CFTR expression and mislocalization in cerulein-induced AP. Our results suggest that the beneficial effects of CFTR correctors and potentiators should be further investigated in AP. KEY POINTS: Cystic fibrosis transmembrane conductance regulator (CFTR) is an important ion channel in epithelial cells. Its malfunction has several serious consequences, like developing or aggravating acute pancreatitis (AP). Here, the localization and expression of CFTR during cerulein-induced AP in mice were investigated and the effects of CFTR corrector (VX-661) and a potentiator (VX-770) on disease severity were determined. CFTR mRNA expression was significantly increased and mislocalization of CFTR protein was observed in AP compared to the control group. Interestingly, pre-treatment of AP mice with VX-661 + VX-770 significantly reduced the extent of pancreatic tissue damage by 20-30%. In vitro administration of VX-661 + VX-770 significantly increased the fluid secretion of ducts derived from AP animals. Based on these results, the utilization of CFTR correctors and potentiators should be further investigated in AP.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Pancreatite , Doença Aguda , Aminofenóis , Aminopiridinas , Animais , Benzodioxóis , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Indóis , Camundongos , Mutação , Pancreatite/induzido quimicamente , Pancreatite/tratamento farmacológico , Quinolonas , Índice de Gravidade de Doença
6.
RSC Adv ; 11(21): 12802-12807, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35423835

RESUMO

The first representatives of the new fluorescent boro-ß-carboline family were synthesized by the insertion of the difluoroboranyl group into the oxaza or diaza core. The resulting compounds showed good photophysical properties with fine Stokes-shifts in the range of 38-85 nm with blue and green emission. The energetics of the excitation states and molecular orbitals of two members were investigated by quantum chemical computations suggesting effects for the improved properties of diazaborinino-carbolines over oxazaborolo-carbolines. These properties nominated this chemotype as a new fluorophore for the development of fluorescent probes. As an example, diazaborinino-carbolines were used for the specific labeling of anti-Her2 antibody trastuzumab. The fluorescent conjugate showed a high fluorophore-antibody ratio and was confirmed as a useful tool for labeling and confocal microscopy imaging of tumour cells in vitro together with the ex vivo two-photon microscopy imaging of tumour slices.

7.
Cells ; 9(8)2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32784707

RESUMO

Details of the functional mechanisms of intrinsically disordered proteins (IDPs) in living cells is an area not frequently investigated. Here, we dissect the molecular mechanism of action of an IDP in cells by detailed structural analyses based on an in-cell nuclear magnetic resonance experiment. We show that the ID stress protein (IDSP) A. thaliana Early Response to Dehydration (ERD14) is capable of protecting E. coli cells under heat stress. The overexpression of ERD14 increases the viability of E. coli cells from 38.9% to 73.9% following heat stress (50 °C × 15 min). We also provide evidence that the protection is mainly achieved by protecting the proteome of the cells. In-cell NMR experiments performed in E. coli cells show that the protective activity is associated with a largely disordered structural state with conserved, short sequence motifs (K- and H-segments), which transiently sample helical conformations in vitro and engage in partner binding in vivo. Other regions of the protein, such as its S segment and its regions linking and flanking the binding motifs, remain unbound and disordered in the cell. Our data suggest that the cellular function of ERD14 is compatible with its residual structural disorder in vivo.


Assuntos
Proteínas de Arabidopsis/fisiologia , Escherichia coli/fisiologia , Resposta ao Choque Térmico , Proteínas Intrinsicamente Desordenadas/fisiologia , Arabidopsis/fisiologia , Escherichia coli/genética , Viabilidade Microbiana , Microrganismos Geneticamente Modificados/fisiologia , Chaperonas Moleculares/fisiologia , Ligação Proteica , Domínios Proteicos , Proteoma/metabolismo
8.
J Cancer Educ ; 35(2): 352-358, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-30761445

RESUMO

The aim of this study was to compare the quality of life and school success of adolescent survivors and their classmates. A survey was conducted among 21 cancer survived 12-18-year-old children and 95 of their classmates by using questionnaires covering (a) characteristics of the quality of life; (b) characteristics of the learning process; and (c) level of the fear of cancer recurrence. Significant difference was found in the field of physical and emotional functions but contrary to expected, the members of the control group reported lower values than survivor children. Those children that were teased because of cancer made friends hardly and got involved in social programs with more difficulty. With reference to the level of development of school motivation and the use of learning strategies, it was experienced a significant difference between the two groups only in the field of planning. Our results show that the better the survived children's general quality of life is the better results they achieve at school. Their learning achievement is influenced to a much bigger extent by social functions than their physical disadvantages.


Assuntos
Sobreviventes de Câncer/psicologia , Amigos/psicologia , Aprendizagem , Neoplasias/psicologia , Qualidade de Vida , Estudantes/psicologia , Adolescente , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Neoplasias/terapia , Inquéritos e Questionários
9.
Biochim Biophys Acta Gen Subj ; 1864(3): 129506, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31870857

RESUMO

BACKGROUND: Fully intrinsically disordered plant dehydrin ERD14 can protect enzymes via its chaperone-like activity, but it was not formally linked with enzymes of the plant redox system yet. This is of particular interest, as the level of H2O2 in Arabidopsis plants increases during osmotic stress, which can be counteracted by overexpression of ERD14. METHODS: The proteomic mass-spectrometry analysis of stressed plants was performed to find the candidates affected by ERD14. With cross-linking, microscale thermophoresis, and active-site titration kinetics, the interaction and influence of ERD14 on the function of two target proteins: glutathione transferase Phi9 and catalase was examined. RESULTS: Under osmotic stress, redox enzymes, specifically the glutathione transferase Phi enzymes, are upregulated. Using microscale thermophoresis, we showed that ERD14 directly interacts with GSTF9 with a KD of ~25 µM. ERD14 activates the inactive GSTF9 molecules, protects GSTF9 from oxidation, and can also increases the activity of the enzyme. Aside from GSTF9, we found that ERD14 can also interact with catalase, an important cellular H2O2 scavenging enzyme, with a KD of ~0.13 µM, and protects it from dehydration-induced loss of activity. CONCLUSIONS: We propose that fully intrinsically disordered dehydrin ERD14 might protect and even activate redox enzymes, helping plants to survive oxidative stress under dehydration conditions. GENERAL SIGNIFICANCE: ERD14 has a direct effect on the activity of redox enzymes.


Assuntos
Proteínas de Arabidopsis/metabolismo , Glutationa Transferase/metabolismo , Arabidopsis/enzimologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/fisiologia , Glutationa Transferase/química , Peróxido de Hidrogênio/metabolismo , Espectrometria de Massas , Pressão Osmótica , Oxirredução , Estresse Oxidativo/fisiologia , Proteínas de Plantas/metabolismo , Dobramento de Proteína , Proteômica
10.
Proc Natl Acad Sci U S A ; 116(16): 7889-7898, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30926670

RESUMO

Phase separation of multivalent protein and RNA molecules underlies the biogenesis of biomolecular condensates such as membraneless organelles. In vivo, these condensates encompass hundreds of distinct types of molecules that typically organize into multilayered structures supporting the differential partitioning of molecules into distinct regions with distinct material properties. The interplay between driven (active) versus spontaneous (passive) processes that are required for enabling the formation of condensates with coexisting layers of distinct material properties remains unclear. Here, we deploy systematic experiments and simulations based on coarse-grained models to show that the collective interactions among the simplest, biologically relevant proteins and archetypal RNA molecules are sufficient for driving the spontaneous emergence of multilayered condensates with distinct material properties. These studies yield a set of rules regarding homotypic and heterotypic interactions that are likely to be relevant for understanding the interplay between active and passive processes that control the formation of functional biomolecular condensates.


Assuntos
Proteínas Intrinsicamente Desordenadas , Transição de Fase , RNA , Biologia Computacional , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas Intrinsicamente Desordenadas/fisiologia , Simulação de Dinâmica Molecular , Organelas/química , Organelas/metabolismo , RNA/química , RNA/metabolismo , RNA/fisiologia
11.
Molecules ; 24(3)2019 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-30699990

RESUMO

Whereas the concept of intrinsic disorder derives from biophysical observations of the lack of structure of proteins or protein regions under native conditions, many of our respective concepts rest on proteome-scale bioinformatics predictions. It is established that most predictors work reliably on proteins commonly encountered, but it is often neglected that we know very little about their performance on proteins of microorganisms that thrive in environments of extreme temperature, pH, or salt concentration, which may cause adaptive sequence composition bias. To address this issue, we predicted structural disorder for the complete proteomes of different extremophile groups by popular prediction methods and compared them to those of the reference mesophilic group. While significant deviations from mesophiles could be explained by a lack or gain of disordered regions in hyperthermophiles and radiotolerants, respectively, we found systematic overprediction in the case of halophiles. Additionally, examples were collected from the Protein Data Bank (PDB) to demonstrate misprediction and to help understand the underlying biophysical principles, i.e., halophilic proteins maintain a highly acidic and hydrophilic surface to avoid aggregation in high salt conditions. Although sparseness of data on disordered proteins from extremophiles precludes the development of dedicated general predictors, we do formulate recommendations for how to address their disorder with current bioinformatics tools.


Assuntos
Proteínas/química , Biologia Computacional/métodos , Bases de Dados de Proteínas/estatística & dados numéricos , Modelos Moleculares , Conformação Proteica , Proteoma/análise
12.
Front Mol Biosci ; 5: 83, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30234128

RESUMO

Protein quantification is essential in a great variety of biochemical assays, yet the inherent systematic errors associated with the concentration determination of intrinsically disordered proteins (IDPs) using classical methods are hardly appreciated. Routinely used assays for protein quantification, such as the Bradford assay or ultraviolet absorbance at 280 nm, usually seriously misestimate the concentrations of IDPs due to their distinct and variable amino acid composition. Therefore, dependable method(s) have to be worked out/adopted for this task. By comparison to elemental analysis as the gold standard, we show through the example of four globular proteins and nine IDPs that the ninhydrin assay and the commercial QubitTM Protein Assay provide reliable data on IDP quantity. However, as IDPs can show extreme variation in amino acid composition and physical features not necessarily covered by our examples, even these techniques should only be used for IDPs following standardization. The far-reaching implications of these simple observations are demonstrated through two examples: (i) circular dichroism spectrum deconvolution, and (ii) receptor-ligand affinity determination. These actual comparative examples illustrate the potential errors that can be incorporated into the biophysical parameters of IDPs, due to systematic misestimation of their concentration. This leads to inaccurate description of IDP functions.

13.
Mol Cell ; 65(6): 1044-1055.e5, 2017 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-28306503

RESUMO

Liquid-liquid phase separation (LLPS) of RNA-binding proteins plays an important role in the formation of multiple membrane-less organelles involved in RNA metabolism, including stress granules. Defects in stress granule homeostasis constitute a cornerstone of ALS/FTLD pathogenesis. Polar residues (tyrosine and glutamine) have been previously demonstrated to be critical for phase separation of ALS-linked stress granule proteins. We now identify an active role for arginine-rich domains in these phase separations. Moreover, arginine-rich dipeptide repeats (DPRs) derived from C9orf72 hexanucleotide repeat expansions similarly undergo LLPS and induce phase separation of a large set of proteins involved in RNA and stress granule metabolism. Expression of arginine-rich DPRs in cells induced spontaneous stress granule assembly that required both eIF2α phosphorylation and G3BP. Together with recent reports showing that DPRs affect nucleocytoplasmic transport, our results point to an important role for arginine-rich DPRs in the pathogenesis of C9orf72 ALS/FTLD.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Arginina/metabolismo , Grânulos Citoplasmáticos/metabolismo , Dipeptídeos/metabolismo , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas/metabolismo , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Arginina/química , Proteína C9orf72 , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Grânulos Citoplasmáticos/patologia , DNA Helicases , Dipeptídeos/química , Fator de Iniciação 2 em Eucariotos/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Células HeLa , Humanos , Proteínas Intrinsicamente Desordenadas/química , Gotículas Lipídicas/metabolismo , Fosforilação , Proteínas de Ligação a Poli-ADP-Ribose , Domínios Proteicos , Proteínas/química , RNA/metabolismo , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Fatores de Tempo , Transfecção
14.
Chemphyschem ; 18(6): 677-682, 2017 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-28066974

RESUMO

In this work the groundwork is laid for characterizing the mobility of hydrogen-hydrogen pairs (proton-proton radial vectors) in proteins in the solid state that contain only residual water. In this novel approach, we introduce new ways of analyzing and interpreting data: 1) by representing hydrogen mobility (HM) and melting diagram (MD) data recorded by wide-line 1 H NMR spectroscopic analysis as a function of fundamental temperature (thermal excitation energy); 2) by suggesting a novel mode of interpretation of these parameters that sheds light on details of protein-water interactions, such as the exact amount of water molecules and the distribution of barrier potentials pertaining to their rotational and surface translational mobility; 3) by relying on directly determined physical observables. We illustrate the power of this approach by studying the behavior of two proteins, the structured enzyme lysozyme and the intrinsically disordered ERD14.


Assuntos
Proteínas de Arabidopsis/química , Hidrogênio/química , Muramidase/química , Água/química , Muramidase/metabolismo
15.
PLoS One ; 11(8): e0161970, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27564234

RESUMO

Protein chaperones are molecular machines which function both during homeostasis and stress conditions in all living organisms. Depending on their specific function, molecular chaperones are involved in a plethora of cellular processes by playing key roles in nascent protein chain folding, transport and quality control. Among stress protein families-molecules expressed during adverse conditions, infection, and diseases-chaperones are highly abundant. Their molecular functions range from stabilizing stress-susceptible molecules and membranes to assisting the refolding of stress-damaged proteins, thereby acting as protective barriers against cellular damage. Here we propose a novel technique to test and measure the capability for protective activity of known and putative chaperones in a semi-high throughput manner on a plate reader. The current state of the art does not allow the in vitro measurements of chaperone activity in a highly parallel manner with high accuracy or high reproducibility, thus we believe that the method we report will be of significant benefit in this direction. The use of this method may lead to a considerable increase in the number of experimentally verified proteins with such functions, and may also allow the dissection of their molecular mechanism for a better understanding of their function.


Assuntos
Chaperonas Moleculares/metabolismo , Análise Serial de Proteínas/métodos , Proteínas/metabolismo , Álcool Desidrogenase/química , Álcool Desidrogenase/metabolismo , Citrato (si)-Sintase/química , Citrato (si)-Sintase/metabolismo , L-Lactato Desidrogenase/química , L-Lactato Desidrogenase/metabolismo , Luciferases/química , Luciferases/metabolismo , Chaperonas Moleculares/química , Ligação Proteica , Dobramento de Proteína , Proteínas/química
16.
J Am Chem Soc ; 137(43): 13807-17, 2015 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-26437245

RESUMO

Intrinsically disordered proteins (IDPs) are important for health and disease, yet their lack of net structure precludes an understanding of their function using classical methods. Gas-phase techniques provide a promising alternative to access information on the structure and dynamics of IDPs, but the fidelity to which these methods reflect the solution conformations of these proteins has been difficult to ascertain. Here we use state of the art ensemble techniques to investigate the solution to gas-phase transfer of a range of different IDPs. We show that IDPs undergo a vast conformational space expansion in the absence of solvent to sample a conformational space 3-5 fold broader than in solution. Moreover, we show that this process is coupled to the electrospray ionization process, which brings about the generation of additional subpopulations for these proteins not observed in solution due to competing effects on protein charge and shape. Ensemble methods have permitted a new definition of the solution to gas-phase transfer of IDPs and provide a roadmap for future investigations into flexible systems by mass spectrometry.


Assuntos
Proteínas Intrinsicamente Desordenadas/química , Gases/química , Humanos , Simulação de Dinâmica Molecular , Transição de Fase , Conformação Proteica , Soluções , Espectrometria de Massas por Ionização por Electrospray
17.
Biochem Soc Trans ; 40(5): 963-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22988848

RESUMO

IDPs (intrinsically disordered proteins) represent a unique class of proteins which show diverse molecular mechanisms in key biological functions. The aim of the present mini-review is to summarize IDP chaperones that have increasingly been studied in the last few years, by focusing on the role of intrinsic disorder in their molecular mechanism. Disordered regions in both globular and disordered chaperones are often involved directly in chaperone action, either by modulating activity or through direct involvement in substrate identification and binding. They might also be responsible for the subcellular localization of the protein. In outlining the state of the art, we survey known IDP chaperones discussing the following points: (i) globular chaperones that have an experimentally proven functional disordered region(s), (ii) chaperones that are completely disordered along their entire length, and (iii) the possible mechanisms of action of disordered chaperones. Through all of these details, we chart out how far the field has progressed, only to emphasize the long road ahead before the chaperone function can be firmly established as part of the physiological mechanistic arsenal of the emerging group of IDPs.


Assuntos
Chaperonas Moleculares/química , Chaperonas Moleculares/metabolismo , Animais , Humanos , Conformação Proteica
18.
Biomol NMR Assign ; 5(2): 189-93, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21336827

RESUMO

Dehydrins are a class of stress proteins that belong to the family of Late Embryogenesis Abundant (LEA) proteins in plants, so named because they are highly expressed in late stages of seed formation. In somatic cells, their expression is very low under normal conditions, but increases critically upon dehydration elicited by water stress, high salinity or cold. Dehydrins are thought to be intrinsically disordered proteins, which represents a challenge in understanding their structure-function relationship. Herein we present the backbone (1)H, (15)N and (13)C NMR assignment of the 185 amino acid long ERD14 (Early Response to Dehydration 14), which is a K(3)S-type, typical dehydrin of A. thaliana. Secondary chemical shifts as well as NMR relaxation data show that ERD14 is fully disordered under near native conditions, with short regions of somewhat restricted motion and 5-25% helical propensity. These results suggest that ERD14 may have partially preformed elements for functional interaction with its partner(s) and set the stage for further detailed structural and functional studies of ERD14 both in vitro and in vivo.


Assuntos
Proteínas de Arabidopsis/química , Ressonância Magnética Nuclear Biomolecular , Arabidopsis/química , Isótopos/química , Chaperonas Moleculares , Proteínas de Plantas
19.
Biochem Cell Biol ; 88(2): 167-74, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20453919

RESUMO

Intrinsically disordered proteins (IDPs) are widespread in eukaryotes and fulfill important functions associated with signaling and regulation. Recent evidence points to a special and thus largely disrespected functional capacity of IDPs--that they can assist the folding of other proteins and prevent their aggregation, i.e., that they can act as chaperones. In this paper, we survey current information available on this phenomenon, with particular focus on (i) the structure and function of IDPs in general, (ii) disordered chaperones in plants, (iii) disordered chaperones in other organisms spanning from insects to mammals, (iv) the possible mechanisms of action of disordered chaperones, and (v) the possibility of two-faced (Janus) chaperone activity of disordered chaperones, which can assist the folding of both RNA and protein substrates. The evidence is most conclusive in the case of plant stress proteins, such as late embryogenesis abundant (LEA) proteins or dehydrins. We will show that the cellular function of LEA proteins in mitigating the damage caused by stress is clear; nevertheless, experiments carried out in vivo must be extended and the molecular mechanism of the action of IDP chaperones also requires clarification. Using these details, we chart out how far the field has progressed only to emphasize the long road ahead before chaperone function can be firmly established as part of the physiological mechanistic arsenal of the emerging group of IDPs.


Assuntos
Chaperoninas/química , Chaperoninas/metabolismo , Plantas/metabolismo , Animais , Plantas/química , Dobramento de Proteína
20.
Psychoneuroendocrinology ; 34(6): 947-52, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19261388

RESUMO

Cognitive functions such as memory are quantitative traits in human, and have both genetic and environmental influences. Testosterone has been implicated in the modulation of memory function. Therefore, genetic variation which influences testosterone signaling may modulate memory function. The principal receptor for testosterone is the androgen receptor, the gene for which maps to the X chromosome. In the present study, we hypothesized that common variation in two functional polymorphisms in the androgen receptor gene, the polyglutamine (CAG) and/or polyglycine (GGN) repeats, would influence memory function in healthy subjects. Variation in length of either repeat modulates the function of the AR gene, either by changing the amount of protein produced, by altering transactivation of the receptor or by producing toxic polyglycine or polyglutamine fragments. In order to test this hypothesis, we analyzed 449 healthy Chinese individuals. CAG repeats were not associated with memory performance. However we observed a significant association between GGN repeats and Immediate Logical Memory (chi(2)=23.6, d.f.=7, p=0.001) and Delayed Logical Memory (chi(2)=16.3, d.f.=7, p=0.022). The association of GGN repeats with Immediate Logical Memory remained significant after 6000 permutation corrections (p=0.013). There was also a sex difference, as association between GGN repeats and memory was observed only in females (p=0.002 for Immediate and p=0.014 for Delayed Logical Memory), but not in males (p=0.31 and 0.83, respectively). We conclude that functional variation of the androgen receptor gene is able to modulate memory function in women.


Assuntos
Povo Asiático/genética , Memória/fisiologia , Peptídeos/genética , Polimorfismo Genético , Receptores Androgênicos/genética , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético/fisiologia , Sequências Repetitivas de Ácido Nucleico/genética , Caracteres Sexuais , Análise e Desempenho de Tarefas , Adulto Jovem
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