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1.
Artigo em Inglês | MEDLINE | ID: mdl-39185651

RESUMO

INTRODUCTION: The 70 kDa heat shock proteins (Hsp70) are ubiquitous molecules that play central roles in protein homeostasis. Their nucleotide-binding domains (NBD) are associated with the J domains of 40 kDa co-chaperone 'HSP40' in performing their functions. Interruption of this interaction significantly impacts the critical ATPase activity of Hsp70s, making them dysfunctional. METHODS: MAL2-11B is a dihydropyrimidine derivative that blocks Hsp70-Hsp40 interaction and hence holds the potential to be used as a drug. This Hsp70 inhibitor is a structural analogue of MAL3-101 that has proven anti-cancer and antiparasitic activity. MAL2-11B is predicted to have better drug-likeness, solubility, and absorption properties than MAL3-101. In the present study, we have therefore explored the potential of MAL2-11B as an antimalarial by using in silico tools. RESULTS: Molecular docking of MAL2-11B with all Plasmodium falciparum Hsp70 (PfHsp70) proteins revealed its preferential affinity for two out of four homologs at the nucleotide-binding site. Detailed analysis of the docked complexes helped us to predict the kind of protein-inhibitor interactions and specific amino acid residues involved in binding. CONCLUSION: After in vitro validation, these data may be used as the groundwork for the design and development of new inhibitors and drugs against malaria.

2.
Protein Pept Lett ; 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38910420

RESUMO

Malaria caused by Plasmodium falciparum (Pf) is an illness that contributes significantly to the global health burden. Pf makes significant alterations to the host cell to meet its metabolic demands and escape the immune response of the host. These include the export of a large number of parasite proteins to the infected Red Blood Cells (iRBC). Variable Surface Antigens (VSAs), which are highly polymorphic protein families with important roles in immune evasion, form an important component of the exported proteins. A total of five protein families constitute the VSAs, viz. PfEMP1 (Pf erythrocyte membrane protein 1), RIFIN (repetitive interspersed family), STEVOR (sub-telomeric open reading frame), SURFIN (surface-associated interspersed gene family), and PfMC-2TM (Pf Maurer's cleft two transmembrane). With orthologues present in various simian-infecting species, VSAs take up a variety of domain topologies and organizational structures while exhibiting differential expressions throughout the parasite life cycle. Their expression varies across clinical isolates and laboratory strains, which suggests their crucial role in host cell survival and defense. Members of VSAs are reported to contribute significantly to disease pathogenesis through immune evasion processes like cytoadherence, iRBC sequestration in the host vasculature, rosetting, reduced erythrocyte deformability, and direct immunosuppression. In this study, we have gathered information on various aspects of VSAs, like their orthologues, domain architecture, surface topology, functions and interactions, and three-dimensional structures, while emphasizing discoveries in the field. Considering the vast repertoire of Plasmodial VSAs with new emergent functions, a lot remains unknown about these families and, hence, malaria biology.

3.
Environ Sci Pollut Res Int ; 31(20): 29415-29433, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38575821

RESUMO

Aqueous fluoride ( F - ) pollution is a global threat to potable water security. The present research envisions the development of novel adsorbents from indigenous Limonia acidissima L. (fruit pericarp) for effective aqueous defluoridation. The adsorbents were characterized using instrumental analysis, e.g., TGA-DTA, ATR-FTIR, SEM-EDS, and XRD. The batch-mode study was performed to investigate the influence of experimental variables. The artificial neural network (ANN) model was employed to validate the adsorption. The dataset was fed to a backpropagation learning algorithm of the ANN (BPNN) architecture. The four-ten-one neural network model was considered to be functioning correctly with an absolute-relative-percentage error of 0.633 throughout the learning period. The results easily fit the linearly transformed Langmuir isotherm model with a correlation coefficient ( R 2 ) > 0.997. The maximum F - removal efficiency was found to be 80.8 mg/g at the optimum experimental condition of pH 7 and a dosage of 6 g/L at 30 min. The ANN model and experimental data provided a high degree of correlation ( R 2 = 0.9964), signifying the accuracy of the model in validating the adsorption experiments. The effects of interfering ions were studied with real F - water. The pseudo-second-order kinetic model showed a good fit to the equilibrium dataset. The performance of the adsorbent was also found satisfactory with field samples and can be considered a potential adsorbent for aqueous defluoridation.


Assuntos
Fluoretos , Redes Neurais de Computação , Poluentes Químicos da Água , Purificação da Água , Fluoretos/química , Adsorção , Poluentes Químicos da Água/química , Purificação da Água/métodos , Cinética , Água/química
4.
Curr Protein Pept Sci ; 25(6): 427-437, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38409726

RESUMO

The apicomplexan pathogenic parasite 'Plasmodium falciparum' (Pf) is responsible for most of the malaria related mortality. It resides in and refurbishes the infected red blood cells (iRBCs) for its own survival and to suffice its metabolic needs. Remodeling of host erythrocytes involves alteration of physical and biochemical properties of the membrane and genesis of new parasite induced structures within the iRBCs. The generated structures include knobs and solute ion channels on the erythrocyte surface and specialized organelles i.e. Maurer's clefts (MCs) in the iRBC cytosol. The above processes are mediated by exporting a large repertoire of proteins to the host cell, most of which are transported via MCs, the sorting stations in parasitized erythrocytes. Information about MC biogenesis and the molecules involved in maintaining MC architecture remains incompletely elucidated. Here, we have compiled a list of experimentally known MC resident proteins, several of which have roles in maintaining its architecture and function. Our short review covers available data on the domain organization, orthologues, topology and specific roles of these proteins. We highlight the current knowledge gaps in our understanding of MCs as crucial organelles involved in parasite biology and disease pathogenesis.


Assuntos
Eritrócitos , Malária Falciparum , Plasmodium falciparum , Proteínas de Protozoários , Plasmodium falciparum/metabolismo , Humanos , Eritrócitos/parasitologia , Eritrócitos/metabolismo , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/genética , Malária Falciparum/parasitologia , Malária Falciparum/metabolismo , Animais , Interações Hospedeiro-Parasita , Transporte Proteico , Membrana Eritrocítica/parasitologia , Membrana Eritrocítica/metabolismo
5.
Drug Metab Bioanal Lett ; 17(1): 34-41, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38231055

RESUMO

INTRODUCTION: MKT-077 and its derivatives are rhodacyanine inhibitors that hold potential in the treatment of cancer, neurodegenerative diseases and malaria. These allosteric drugs act by inhibiting the ATPase action of heat shock proteins of 70 kDa (HSP70). MKT-077 accumulates in the mitochondria and displays differential activity against HSP70 homologs. METHODS: The four Plasmodium falciparum HSP70s (PfHSP70) are present in various subcellular locations to perform distinct functions. In the present study, we have used bioinformatics tools to understand the interaction of MKT-077 at the ADP and HEW (2-amino 4 bromopyridine) binding sites on PfHSP70s. Our molecular docking experiments predict that the mitochondrial and endoplasmic reticulum PfHSP70 homologs are likely to bind MKT-077 with higher affinities at their ADP binding sites. RESULTS: Binding analysis indicates that the nature of the identified interactions is primarily hydrophobic. We have also identified specific residues of PfHSP70s that are involved in interacting with the ligand. CONCLUSION: Information obtained in this study may form the foundation for the design and development of MKT-077-based drugs against malaria.


Assuntos
Antimaláricos , Proteínas de Choque Térmico HSP70 , Simulação de Acoplamento Molecular , Plasmodium falciparum , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Antimaláricos/farmacologia , Antimaláricos/química , Sítios de Ligação , Humanos , Rodanina/farmacologia , Rodanina/química , Rodanina/análogos & derivados , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Piridinas , Tiazóis
6.
Int J Phytoremediation ; 26(1): 45-51, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37291794

RESUMO

The present research work approaches the accumulation of fluoride ions from contaminated water using an aquatic plant Monochoria hastate L. in hydroponic culture. A design of experiment (DOE) has been adopted and an analysis of variance has been conducted to establish the statistical significance of various process parameters. The different experimental factors are root and shoot (Factor A), fluoride concentration (Factor B), and experimental days (Factor C) largely influence the output response. Plants treated with 5 mg/L of fluoride solutions accumulated the highest concentration in root biomass 1.23 mg/gm, and shoot biomass 0.820 mg/gm, dry weight after 21 days' experimentation. The accumulation mechanism and potentiality of treated plants depend on root cells of the plasma membrane and energy-capturing molecules of adenosine triphosphate. Monochoria hastate L. root biomass was characterized to confirm the accumulation of fluoride ions in the experimented plants using scanning electron micrographs-energy dispersive spectrum (SEM-EDS), and Fourier transforms infrared analysis (FTIR) analysis.


The novelty of this study is the high fluoride accumulation efficiency in hydroponic treatment by Monochoria hastate L an excellent choice for phytoremediation technique. The Design of Experiment (DOE) has a good approach for the optimization of fluoride in the accumulation process. The maximum absorption of fluoride ions in root biomass is 1.23 mg/gm, and shoot biomass is 0.820 mg/gm, dry weight after 21 days of treatment. To know the fluoride ions in shoot and root biomass are characterized using scanning electron micrographs-energy dispersive spectrum (SEM-EDS), and Fourier transforms infrared analysis (FTIR).


Assuntos
Fluoretos , Água , Fluoretos/análise , Fluoretos/metabolismo , Água/análise , Hidroponia , Biodegradação Ambiental , Biomassa , Raízes de Plantas/química
7.
Protein Pept Lett ; 30(9): 777-782, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37592795

RESUMO

BACKGROUND: Management of gluten intolerance is currently possible only by consumption of a gluten-free diet (GFD) for a lifetime. The scientific community has been searching for alternatives to GFD, like the inclusion of natural proteases with meals or pre-treatment of gluten-containing foods with glutenases. Actinidin from kiwifruit has shown considerable promise in digesting immunogenic gliadin peptides compared to other plant-derived cysteine proteases. METHODS: In this study, we aimed to understand the structural basis for the elevated protease action of actinidin against gliadin peptides by using an in silico approach. RESULTS: Docking experiments revealed key differences between the binding of gliadin peptide to actinidin and papain, which may be responsible for their differential digestive action. CONCLUSION: Sequence comparison of different plant cysteine proteases highlights amino acid residues surrounding the active site pocket of actinidin that are unique to this molecule and hence likely to contribute to its digestive properties.


Assuntos
Cisteína Endopeptidases , Gliadina , Cisteína Endopeptidases/metabolismo , Glutens/metabolismo , Peptídeos
8.
Biotechnol Appl Biochem ; 70(5): 1741-1753, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37183365

RESUMO

Alkaline proteases from microbial sources have been found suitable for diverse industrial applications, with serine proteases being the most common enzymes used in the detergent industry. In the present study, we have purified and characterized an extracellular alkaline serine protease from Microbacterium paraoxydans sp. SKS10. The protease was purified using ammonium sulfate precipitation followed by different chromatography techniques (fold purification 6.919). Km and Vmax for the protease were determined to be 0.183 mg/mL and 4.904 U/mL, respectively. This enzyme is a thermostable high molecular weight (∼109.4 kDa) protease which has maximal activity at 60°C, and above pH 10. Inhibitor assays revealed the enzyme to be a serine protease whose activity increased by 2.5-fold in the presence of EDTA. This enzyme remained active in the presence of various metal salts and organic solvents and was compatible with commercially available laundry detergents highlighting its potential for use in the detergent industry.


Assuntos
Detergentes , Serina Proteases , Serina Proteases/química , Detergentes/química , Peso Molecular , Endopeptidases/química , Endopeptidases/metabolismo , Proteínas de Bactérias/química , Concentração de Íons de Hidrogênio , Estabilidade Enzimática , Temperatura
9.
Environ Sci Pollut Res Int ; 30(9): 23997-24012, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36331741

RESUMO

The present research work approaches the removal of fluoride from aqueous medium using neutralized activated red mud (NARM) in a continuous fixed bed column. Artificial neural network (ANN) technique was applied effectively for optimization of the model for the practicability of the removal process. The consequences of various experimental variables, like bed length, adsorbate concentration, experimental time, and adsorbate solution flow rate are studied to know the breakthrough point and saturation times. The highest removal potentiality of NARM was considered to be 3.815 mg g-1 of F- in the bed height of 15 cm, starting concentration 1 ppm, susceptible time 120 min, adsorbate solution flow rate 0.5 mL min-1, and constant room temperature, respectively. Bohart-Adams and Thomas models were considered to describe the fixed bed column effect to the bed height and adsorbate concentrations. The experimental data were applied to a back propagation (BP) learning algorithm programme with a four-seven-one architecture model. The artificial neural network model was considered to be functioning correctly as absolute relative percentage error throughout the learning period. Differentiation between the predicted outcomes from ANN model and actual results from experimental analysis affords a high degree of correlation (R2 = 0.998) stipulating that the model was able to predict the adsorption efficiency. Experimented adsorbent materials were characterized using different instrumental analysis that is scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD).


Assuntos
Poluentes Químicos da Água , Purificação da Água , Fluoretos , Purificação da Água/métodos , Redes Neurais de Computação , Algoritmos , Adsorção , Água , Poluentes Químicos da Água/análise
10.
Water Sci Technol ; 85(1): 515-534, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35050899

RESUMO

The conventional method of water treatment using activated carbon from several sources has been focused on extensively in the last two decades. However, rare attention has been noticed on natural adsorbents such as plant leaves. Therefore, the Psidium guajava (guava) leaf has been investigated to understand its adsorption efficacy for Arsenic (III) [As(III)] in this study. The effect of process variables, e.g., pH, concentration of metal ion, adsorbent's particle size, and dosages, are evaluated. Experiments are carried out in batch mode, and the individual and combined parameter's impact on adsorption have been discussed. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) is used to characterize the adsorbent's surface. Freundlich and Langmuir's isotherms are used for adsorption equilibrium study. The adsorption parameters are optimized by establishing a regression correlation using central composite design (CCD) of response surface methodology (RSM). The analysis of variance (ANOVA) suggests a high regression coefficient (R2 = 0.9249) for the removal of As(III). Particle size of 0.39 mm; adsorbent's height of 10 cm; metal ion concentration of 30 ppm, and pH 6 are optimized to remove 90.88% As(III) from aqueous solution. HCl is evaluated as a potential solvent for desorption of arsenic from the desorption study.


Assuntos
Arsênio , Psidium , Poluentes Químicos da Água , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Folhas de Planta/química , Pós , Poluentes Químicos da Água/análise
11.
Water Sci Technol ; 84(1): 55-65, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34280154

RESUMO

In this study, the removal of hexavalent chromium from aqueous solution were examined using activated charcoal derived from Sapindus trifoliate L fruit biomass in continuous fixed-bed column studies. The activated S. trifoliate L fruit charcoal was prepared by treating the fruit powder using concentrated nitric acid solution. Experiments were performed to investigate the effect of bed height and initial concentration on the breakthrough and saturation times. The breakthrough and saturation time increases with increase in bed height and initial concentration of chromium solutions. The maximum adsorption capacity of S. trifoliate L charcoal for hexavalent chromium was found to be 1.719 mg/g in the bed height 15 cm and initial concentration 10 mg/L, respectively. Column data required at various conditions were explained using Bohart-Adams and Thomas model. Two models were found to be suitable to describe the definite part of the dynamic behaviour of the column with regard to bed-height and initial concentration of hexavalent chromium. On comparison of Adjusted R2 and estimated standard error, the Thomas model was found to best-fitted model and can be used to predict the adsorption of the hexavalent chromium in fixed-bed column studies. Activated S. trifoliate L fruit charcoal was characterised by SEM-EDX and FTIR analysis.


Assuntos
Sapindus , Poluentes Químicos da Água , Purificação da Água , Adsorção , Biomassa , Carvão Vegetal , Cromo/análise , Frutas/química , Cinética , Poluentes Químicos da Água/análise
12.
Artigo em Inglês | MEDLINE | ID: mdl-31448272

RESUMO

Enzymes have replaced or decreased usage of toxic chemicals for industrial and medical applications leading toward sustainable chemistry. In this study, we report purification and characterization of a biofilm degrading protease secreted by Microbacterium sp. SKS10. The protease was identified as a metalloprotease, Peptidase M16 using mass spectrometry. It showed optimum activity at 60°C, pH 12 and retained its activity in the presence of various salts and organic solvents. The enzyme was able to degrade biofilms efficiently at enzyme concentration lower than other known enzymes such as papain, trypsin and α-amylase. The presence of this protease increased the accessibility of antibiotics inside the biofilm, and was found to be non-cytotoxic toward human epidermoid carcinoma cells (A431) at the effective concentration for biofilm degradation. Thus, this protease may serve as an effective tool for management of biofilms.

13.
Comput Biol Chem ; 83: 107099, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31430682

RESUMO

Expression of heat shock proteins in Plasmodium falciparum (Pf) increases during febrile episodes to play key roles in several necessary cellular processes. 'PFA0660w-PfHsp70-x', an exported chaperone pair is known to co-localize to specialized intracellular structures termed J-dots, and has been implicated in trafficking of the major virulence factor, PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1) across the host cell. This article highlights for the first time detailed structural analysis of PFA0660w-PfHsp70-x chaperone pair to better understand their binding mechanism. Here, we have modeled reliable molecular structures for the complete conserved region of PFA0660w and PfHsp70-x. These structures were evaluated by different structure verification tools followed by molecular dynamics (MD) simulations. The model of PFA0660w was subjected to docking with PfHsp70-x using Haddock to reveal a number of residues crucial for their bipartite interaction, and also performed MD simulations on the complex. The peptide binding clefts of PFA0660w and its other Plasmodium species homologs were found to be bigger than their counterparts in higher eukaryotes like yeast, humans and C. parvum. Based on our results, we propose a model for PFA0660w-PfHsp70-x interaction and a mechanism of substrate binding, and compare it with its dimeric human counterparts. Owing to these striking structural differences between the host and parasite chaperones, such information on the essential Hsp40 and its partner Hsp70 may form the basis for rational drug design against fatal malaria.


Assuntos
Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP70/química , Plasmodium falciparum/química , Humanos , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica
14.
Int J Biol Macromol ; 138: 996-1005, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31356937

RESUMO

Several exported Plasmodium falciparum (Pf) proteins contribute to malaria biology through their involvement in cytoadherence, immune evasion and host cell remodelling. Many of these exported proteins and other host molecules are present in iRBC (infected red blood cell) generated extracellular vesicles (EVs), which are responsible for host cell modification and parasite development. CX3CL1 binding proteins (CBPs) present on the surface of iRBCs have been reported to contribute to cytoadhesion by binding with the chemokine 'CX3CL1' via their extracellular domains. Here, we have characterized the cytoplasmic domain of CBP2 to understand its function in parasite biology using biochemical and biophysical methods. Recombinant cytoplasmic CBP2 (cCBP2) binds nucleic acids showing interaction with DNA/RNA. cCBP2 shows dimer formation under non-reducing conditions highlighting the role of disulphide bonds in its oligomerization while ATP binding leads to structural changes in the protein. In vitro interaction studies depict its binding with a Maurer's cleft resident protein 'PfSBP1', which is influenced by ATP binding of cCBP2. Our results suggest CBP2 as a two-transmembrane (2TM) receptor responsible for targeting EVs and delivering cargo to host endothelial cells. We propose CBP2 as an important molecule having roles in cytoadherence and immune modulation through its extracellular and cytoplasmic domains respectively.


Assuntos
Quimiocina CX3CL1/metabolismo , Ácidos Nucleicos/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Quimiocina CX3CL1/química , Humanos , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Modelos Biológicos , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas de Protozoários/química
15.
Sci Rep ; 9(1): 2664, 2019 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-30804381

RESUMO

Lethality of Plasmodium falciparum caused malaria results from 'cytoadherence', which is mainly effected by exported Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family. Several exported P. falciparum proteins (exportome) including chaperones alongside cholesterol rich microdomains are crucial for PfEMP1 translocation to infected erythrocyte surface. An exported Hsp40 (heat shock protein 40) 'PFA0660w' functions as a co-chaperone of 'PfHsp70-x', and these co-localize to specialized intracellular mobile structures termed J-dots. Our studies attempt to understand the function of PFA0660w-PfHsp70-x chaperone pair using recombinant proteins. Biochemical assays reveal that N and C-terminal domains of PFA0660w and PfHsp70-x respectively are critical for their activity. We show the novel direct interaction of PfHsp70-x with the cytoplasmic tail of PfEMP1, and binding of PFA0660w with cholesterol. PFA0660w operates both as a chaperone and lipid binding molecule via its separate substrate and cholesterol binding sites. PfHsp70-x interacts with cholesterol bound PFA0660w and PfEMP1 simultaneously in vitro to form a complex. Collectively, our results and the past literature support the hypothesis that PFA0660w-PfHsp70-x chaperone pair assists PfEMP1 transport across the host erythrocyte through cholesterol containing 'J-dots'. These findings further the understanding of PfEMP1 export in malaria parasites, though their in vivo validation remains to be performed.


Assuntos
Colesterol/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Chaperonas Moleculares/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP70/genética , Humanos , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Lipídeos de Membrana/metabolismo , Modelos Moleculares , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidade , Ligação Proteica , Domínios Proteicos , Transporte Proteico , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Virulência , Fatores de Virulência/química , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
16.
Int J Biol Macromol ; 126: 673-684, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30599160

RESUMO

The inner membrane complex (IMC) is a defining feature of apicomplexans comprising of lipid and protein components involved in gliding motility and host cell invasion. Motility of Plasmodium parasites is accomplished by an actin and myosin based glideosome machinery situated between the parasite plasma membrane (PPM) and IMC. Here, we have studied in vivo expression and localization of a Plasmodium falciparum (Pf) IMC protein 'PfIMC1l' and characterized it functionally by using biochemical assays. We have identified cytoskeletal protein 'actin' and motor protein 'myosin' as novel binding partners of PfIMC1l, alongside its interaction with the lipids 'cholesterol' and 'phosphatidyl-inositol 4, 5 bisphosphate' (PIP2). While actin and myosin compete for interaction with PfIMC1l, actin and either of the lipids (cholesterol or PIP2) simultaneously bind PfIMC1l. Interestingly, PfIMC1l showed enhanced binding with actin in the presence of calcium ions, and displayed direct binding with calcium. Based on our in silico analysis and experimental data showing PfIMC1l-actin/myosin and PfIMC1l-lipid interactions, we propose that this protein may anchor the IMC membrane with the parasite gliding apparatus. Considering its binding with key proteins involved in motility viz. myosin and actin (with calcium dependence), we suggest that PfIMC1l may have a role in the locomotion of Plasmodium.


Assuntos
Actinas/metabolismo , Citoesqueleto/metabolismo , Lipídeos de Membrana/metabolismo , Miosinas/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Ligação Competitiva , Cálcio/metabolismo , Colesterol/metabolismo , Soros Imunes/metabolismo , Íons , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Modelos Biológicos , Fosfatidilinositol 4,5-Difosfato/metabolismo , Ligação Proteica , Domínios Proteicos , Proteínas de Protozoários/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Soluções
17.
Pathog Dis ; 76(9)2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30576479

RESUMO

Plasmodium falciparum (Pf) proteins exported to infected erythrocytes are key effectors of malaria pathogenesis. These include the PfEMP1 (Pf erythrocyte membrane protein 1) protein family that affects malaria-related mortality through cytoadhesion and parasite immune evasion. Parasites also induce membranous structures called Maurer's clefts (MC) in infected erythrocytes to compensate the lack of host protein synthetic and export machinery. PfEMP1 export is mediated by a myriad of proteins including Pf skeleton binding protein 1 (PfSBP1) and PF70, a hypothetical 16 family member. Here, we aim to understand the function of the only other exported PEXEL-positive hyp16 member 'PfJ23'. Our in vitro and in silico data suggest this protein to be mostly α-helical while displaying different oligomeric forms under reducing and non-reducing conditions. We show coherent expression, partial co-localization and direct interaction of purified PfSBP1 with recombinant and native PfJ23. Recombinant and parasite-expressed PfJ23 also bind to the cytoplasmic tail of PfEMP1, and they seem to partly co-localize during parasite development. Both novel binding partners interact simultaneously with PfJ23 in vitro to form a complex. Our results suggest a probable role for PfJ23 in export of PEXEL-negative proteins like PfSBP1 and PfEMP1, furthering our understanding of malaria biology.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Membrana/metabolismo , Plasmodium falciparum/metabolismo , Multimerização Proteica , Proteínas de Protozoários/metabolismo , Fatores de Virulência/metabolismo , Sítios de Ligação , Ligação Proteica , Conformação Proteica , Mapeamento de Interação de Proteínas , Transporte Proteico , Fatores de Virulência/química , Fatores de Virulência/genética
18.
PLoS One ; 12(11): e0188724, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29190780

RESUMO

Proteases are one of the largest groups of hydrolytic enzymes constituting about 60% of total worldwide sales of industrial enzymes due to their wide applications in detergent, leather, textile, food and pharmaceutical industry. Microbial proteases have been preferred over animal and plant proteases because of their fundamental features and ease in production. Bacillus infantis SKS1, an alkaline protease producing bacteria has been isolated from garden soil of north India and identified using morphological, biochemical and molecular methods. 16S rDNA sequence amplified using universal primers has 99% sequence identity with corresponding gene sequence of Bacillus infantis strain FM 34 and Bacillus sp. Beige. The bacterial culture and its 16S rDNA gene sequence have been deposited to Microbial Culture Collection (Pune, India) with accession number MCC 3035 and GenBank with accession number KR092197 respectively. The partially purified extract of Bacillus infantis SKS1 was thermostable and active in presence of Mg2+, acetyl acetone and laundry detergents implicating its application in industry. Production of these enzymes using this strain was maximized by optimization of various parameters including temperature, pH, media components and other growth conditions. Our results show that fructose and dextrose serve as the best carbon sources for production of these enzymes, highlighting the use of this strain for enzyme production utilizing relatively inexpensive substrates like beet molasses and corn steep liquor. Additionally, this strain showed maximum production of enzymes at 40°C similar to bacterial species used for commercial production of alkaline proteases. Characterization of alkaline proteases from this strain of Bacillus infantis and optimization of parameters for its production would help in understanding its industrial application and large-scale production.


Assuntos
Bacillus/enzimologia , Proteínas de Bactérias/metabolismo , Endopeptidases/metabolismo , Microbiologia do Solo , Detergentes/química
19.
Metab Brain Dis ; 31(2): 225-37, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26746434

RESUMO

One of the most common central nervous system diseases in tropical countries is cerebral malaria (CM). Malaria is a common protozoan infection that is responsible for enormous worldwide mortality and economic burden on the society. Episodes of Plasmodium falciparum (Pf) caused CM may be lethal, while survivors are likely to suffer from persistent debilitating neurological deficits, especially common in children. In this review article, we have summarized the various symptoms and manifestations of CM in children and adults, and entailed the molecular basis of the disease. We have also emphasized how pathogenesis of the disease is effected by the parasite and host responses including blood brain barrier (BBB) disruption, endothelial cell activation and apoptosis, nitric oxide bioavailability, platelet activation and apoptosis, and neuroinflammation. Based on a few recent studies carried out in experimental mouse malaria models, we propose a basis for the neurological deficits and sequelae observed in human cerebral malaria, and summarize how existing drugs may improve prognosis in affected individuals.


Assuntos
Barreira Hematoencefálica/metabolismo , Inflamação/metabolismo , Malária Cerebral/metabolismo , Óxido Nítrico/metabolismo , Plasmodium falciparum/metabolismo , Animais , Barreira Hematoencefálica/patologia , Modelos Animais de Doenças , Humanos
20.
Indian J Pediatr ; 81(8): 805-7, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24271875

RESUMO

The authors studied the outcome of 108 infants < 6 mo with severe acute malnutrition (SAM) admitted in the Nutritional Rehabilitation Centres (NRC) at a teaching hospital. The most common symptom that the children presented with, was acute diarrhoea (35.2 %) followed by failure to gain weight (26.9 %). Seventy five (69.4 %) infants were cured after nutritional rehabilitation and 29 (26.8 %) were non responders. Fifty two (48 %) infants showed good weight gain after proper counseling or supplementary suckling technique alone.


Assuntos
Transtornos da Nutrição do Lactente/reabilitação , Doença Aguda , Humanos , Lactente , Aumento de Peso
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