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1.
Int J Phytoremediation ; 26(1): 45-51, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37291794

RESUMEN

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).


Asunto(s)
Fluoruros , Agua , Fluoruros/análisis , Fluoruros/metabolismo , Agua/análisis , Hidroponía , Biodegradación Ambiental , Biomasa , Raíces de Plantas/química
2.
Biotechnol Appl Biochem ; 70(5): 1741-1753, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37183365

RESUMEN

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.


Asunto(s)
Detergentes , Serina Proteasas , Serina Proteasas/química , Detergentes/química , Peso Molecular , Endopeptidasas/química , Endopeptidasas/metabolismo , Proteínas Bacterianas/química , Concentración de Iones de Hidrógeno , Estabilidad de Enzimas , Temperatura
3.
Water Sci Technol ; 85(1): 515-534, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35050899

RESUMEN

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.


Asunto(s)
Arsénico , Psidium , Contaminantes Químicos del Agua , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Hojas de la Planta/química , Polvos , Contaminantes Químicos del Agua/análisis
4.
Water Sci Technol ; 84(1): 55-65, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34280154

RESUMEN

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.


Asunto(s)
Sapindus , Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Biomasa , Carbón Orgánico , Cromo/análisis , Frutas/química , Cinética , Contaminantes Químicos del Agua/análisis
5.
Metab Brain Dis ; 31(2): 225-37, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26746434

RESUMEN

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.


Asunto(s)
Barrera Hematoencefálica/metabolismo , Inflamación/metabolismo , Malaria Cerebral/metabolismo , Óxido Nítrico/metabolismo , Plasmodium falciparum/metabolismo , Animales , Barrera Hematoencefálica/patología , Modelos Animales de Enfermedad , Humanos
6.
Curr Protein Pept Sci ; 25(6): 427-437, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38409726

RESUMEN

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.


Asunto(s)
Eritrocitos , Malaria Falciparum , Plasmodium falciparum , Proteínas Protozoarias , Plasmodium falciparum/metabolismo , Humanos , Eritrocitos/parasitología , Eritrocitos/metabolismo , Proteínas Protozoarias/metabolismo , Proteínas Protozoarias/genética , Malaria Falciparum/parasitología , Malaria Falciparum/metabolismo , Animales , Interacciones Huésped-Parásitos , Transporte de Proteínas , Membrana Eritrocítica/parasitología , Membrana Eritrocítica/metabolismo
7.
Protein Pept Lett ; 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38910420

RESUMEN

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.

8.
Environ Sci Pollut Res Int ; 31(20): 29415-29433, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38575821

RESUMEN

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.


Asunto(s)
Fluoruros , Redes Neurales de la Computación , Contaminantes Químicos del Agua , Purificación del Agua , Fluoruros/química , Adsorción , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Cinética , Agua/química
9.
Artículo en Inglés | MEDLINE | ID: mdl-38231055

RESUMEN

INTRODUCTION: MKT-077 and its derivatives are rhodacyanine inhibitors that hold po-tential in the treatment of cancer, neurodegenerative diseases and malaria. These allosteric drugs act by inhibiting the ATPase action of heat shock proteins of 70kDa (HSP70). MKT-077 accu-mulates in the mitochondria and displays differential activity against HSP70 homologs. METHODS: The four Plasmodium falciparum HSP70s (PfHSP70) are present in various subcellu-lar 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 bro-mopyridine) binding sites on PfHSP70s. Our molecular docking experiments predict that the mi-tochondrial 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 hy-drophobic. 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 de-velopment of MKT-077-based drugs against malaria.

10.
Environ Sci Pollut Res Int ; 30(9): 23997-24012, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36331741

RESUMEN

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).


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Fluoruros , Purificación del Agua/métodos , Redes Neurales de la Computación , Algoritmos , Adsorción , Agua , Contaminantes Químicos del Agua/análisis
11.
Protein Pept Lett ; 30(9): 777-782, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37592795

RESUMEN

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.


Asunto(s)
Cisteína Endopeptidasas , Gliadina , Cisteína Endopeptidasas/metabolismo , Glútenes/metabolismo , Péptidos
12.
J Environ Manage ; 91(9): 1883-91, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20580863

RESUMEN

A laboratory study was conducted to investigate the efficiency of hydroxyapatite (HAP) towards removal of nitrate from synthetic nitrate solution. In the present research HAP synthesized from egg-shell was characterized using SEM, XRD, FTIR and TGA-DSC. The removal of nitrate was 96% under neutral conditions, using 0.3 g of adsorbent in 100 mL of nitrate solution having an initial concentration of 100 mg/L. An adsorption kinetic study revealed that the adsorption process followed first order kinetics. Adsorption data were fitted to a linearly transformed Langmuir isotherm with correlation coefficient (R(2))>0.98. Thermodynamic parameters were also calculated to study the effect of temperature on the removal process. In order to understand the adsorption type, equilibrium data were tested with the Dubinin-Radushkevich isotherm. The process was rapid and equilibrium was established within the first 40 min.


Asunto(s)
Durapatita/química , Nitratos/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Difusión , Estudios de Factibilidad , Concentración de Iones de Hidrógeno , Cinética , Temperatura
13.
BMC Genomics ; 10: 68, 2009 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-19200392

RESUMEN

BACKGROUND: Ribosome biogenesis is an energy consuming and stringently controlled process that involves hundreds of trans-acting factors. Small nucleolar RNAs (snoRNAs), important components of ribosome biogenesis are non-coding guide RNAs involved in rRNA processing, nucleotide modifications like 2'-O-ribose methylation, pseudouridylation and possibly gene regulation. snoRNAs are ubiquitous and are diverse in their genomic organization, mechanism of transcription and process of maturation. In vertebrates, most snoRNAs are present in introns of protein coding genes and are processed by exonucleolytic cleavage, while in plants they are transcribed as polycistronic transcripts. RESULTS: This is a comprehensive analysis of malaria parasite snoRNA genes and proteins that have a role in ribosomal biogenesis. Computational and experimental approaches have been used to identify several box C/D snoRNAs from different species of Plasmodium and confirm their expression. Our analyses reveal that the gene for endoribonuclease Rnt1 is absent from Plasmodium falciparum genome, which indicates the existence of alternative pre-rRNA processing pathways. The structural features of box C/D snoRNAs are highly conserved in Plasmodium genus; however, unlike other organisms most parasite snoRNAs are present in single copy. The genomic localization of parasite snoRNAs shows mixed patterns of those observed in plants, yeast and vertebrates. We have localized parasite snoRNAs in untranslated regions (UTR) of mRNAs, and this is an unprecedented and novel genetic feature. Akin to mammalian snoRNAs, those in Plasmodium may also behave as mobile genetic elements. CONCLUSION: This study provides a comprehensive overview on trans-acting genes involved in ribosome biogenesis and also a genetic insight into malaria parasite snoRNA genes.


Asunto(s)
Plasmodium falciparum/genética , ARN Protozoario/genética , ARN Nucleolar Pequeño/genética , Ribosomas/genética , Regiones no Traducidas 3'/genética , Animales , Secuencia de Bases , Perfilación de la Expresión Génica , Genes Protozoarios , Genoma de Protozoos , Datos de Secuencia Molecular , Análisis de Secuencia de ARN
14.
Comput Biol Chem ; 83: 107099, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31430682

RESUMEN

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.


Asunto(s)
Proteínas del Choque Térmico HSP40/química , Proteínas HSP70 de Choque Térmico/química , Plasmodium falciparum/química , Humanos , Simulación de Dinámica Molecular , Unión Proteica , Conformación Proteica
15.
Artículo en Inglés | MEDLINE | ID: mdl-31448272

RESUMEN

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.

16.
Int J Biol Macromol ; 138: 996-1005, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31356937

RESUMEN

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.


Asunto(s)
Quimiocina CX3CL1/metabolismo , Ácidos Nucleicos/metabolismo , Plasmodium falciparum/metabolismo , Proteínas Protozoarias/metabolismo , Adenosina Trifosfato/metabolismo , Secuencia de Aminoácidos , Quimiocina CX3CL1/química , Humanos , Malaria Falciparum/metabolismo , Malaria Falciparum/parasitología , Modelos Biológicos , Modelos Moleculares , Unión Proteica , Conformación Proteica , Dominios y Motivos de Interacción de Proteínas , Proteínas Protozoarias/química
17.
Sci Rep ; 9(1): 2664, 2019 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-30804381

RESUMEN

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.


Asunto(s)
Colesterol/metabolismo , Proteínas del Choque Térmico HSP40/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Chaperonas Moleculares/metabolismo , Plasmodium falciparum/metabolismo , Proteínas Protozoarias/metabolismo , Secuencia de Aminoácidos , Eritrocitos/metabolismo , Eritrocitos/parasitología , Proteínas del Choque Térmico HSP40/química , Proteínas del Choque Térmico HSP40/genética , Proteínas HSP70 de Choque Térmico/química , Proteínas HSP70 de Choque Térmico/genética , Humanos , Malaria Falciparum/metabolismo , Malaria Falciparum/parasitología , Lípidos de la Membrana/metabolismo , Modelos Moleculares , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidad , Unión Proteica , Dominios Proteicos , Transporte de Proteínas , Proteínas Protozoarias/química , Proteínas Protozoarias/genética , Virulencia , Factores de Virulencia/química , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
18.
Int J Biol Macromol ; 126: 673-684, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-30599160

RESUMEN

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.


Asunto(s)
Actinas/metabolismo , Citoesqueleto/metabolismo , Lípidos de la Membrana/metabolismo , Miosinas/metabolismo , Plasmodium falciparum/metabolismo , Proteínas Protozoarias/metabolismo , Unión Competitiva , Calcio/metabolismo , Colesterol/metabolismo , Sueros Inmunes/metabolismo , Iones , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Modelos Biológicos , Fosfatidilinositol 4,5-Difosfato/metabolismo , Unión Proteica , Dominios Proteicos , Proteínas Protozoarias/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Soluciones
19.
Pathog Dis ; 76(9)2018 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-30576479

RESUMEN

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.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas de la Membrana/metabolismo , Plasmodium falciparum/metabolismo , Multimerización de Proteína , Proteínas Protozoarias/metabolismo , Factores de Virulencia/metabolismo , Sitios de Unión , Unión Proteica , Conformación Proteica , Mapeo de Interacción de Proteínas , Transporte de Proteínas , Factores de Virulencia/química , Factores de Virulencia/genética
20.
PLoS One ; 12(11): e0188724, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29190780

RESUMEN

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.


Asunto(s)
Bacillus/enzimología , Proteínas Bacterianas/metabolismo , Endopeptidasas/metabolismo , Microbiología del Suelo , Detergentes/química
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