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1.
Curr Issues Mol Biol ; 44(11): 5260-5276, 2022 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-36354670

RESUMEN

Coronavirus 2019 (COVID-19) disease management is highly dependent on the immune status of the infected individual. An increase in the incidence of depression has been observed during the ongoing COVID-19 pandemic. Autoantibodies against in vitro reactive oxygen species (ROS) modified BSA and Lys as well as antibodies against receptor binding domain subunit S1 (S1-RBD) (S1-RBD-Abs) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were estimated using direct binding and competition ELISA. Serum samples were also tested for fasting blood glucose (FBG), malondialdehyde (MDA), carbonyl content (CC), interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Significant structural changes were observed in ROS modified BSA and Lys. Female depressed subjects who were also smokers (F-D-S) showed the highest levels of oxidative stress (MDA and CC levels). Similarly, increased levels of autoantibodies against ROS modified proteins were detected in F-D-S subjects, in males who were depressed and in smokers (M-D-S) compared to the other subjects from the rest of the groups. However, contrary to this observation, levels of S1-RBD-Abs were found to be lowest in the F-D-S and M-D-S groups. During the pandemic, large numbers of individuals have experienced depression, which may induce excessive oxidative stress, causing modifications in circulatory proteins. Thus, the formation of neo-antigens is induced, which lead to the generation of autoantibodies. The concomitant effect of increased autoantibodies with elevated levels of IFN-γ and TNF-α possibly tilt the immune balance toward autoantibody generation rather than the formation of S1-RBD-Abs. Thus, it is important to identify individuals who are at risk of depression to determine immune status and facilitate the better management of COVID-19.

2.
Biotechnol Bioeng ; 117(6): 1877-1894, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32159220

RESUMEN

Enzyme engineering is a powerful tool to fine-tune the enzymes. It is a technique by which the stability, activity, and specificity of the enzymes can be altered. The characteristic properties of an enzyme can be amended by immobilization and protein engineering. Among them, protein engineering is the most promising, as in addition to amending the stability and activity, it is the only way to modulate the specificity and stereoselectivity of enzymes. The current review sheds light on protein engineering and the approaches applied for it on the basis of the degree of knowledge of structure and function of enzymes. Enzymes, which have been engineered are also discussed in detail and categorized on the basis of their respective applications. This will give a better insight into the revolutionary changes brought by protein engineering of enzymes in various industrial and environmental processes.


Asunto(s)
Enzimas/genética , Ingeniería de Proteínas/métodos , Animales , Biodegradación Ambiental , Biotecnología/métodos , Evolución Molecular Dirigida/métodos , Activación Enzimática , Estabilidad de Enzimas , Terapia Enzimática , Enzimas/química , Enzimas/metabolismo , Humanos
3.
Prep Biochem Biotechnol ; 50(5): 460-467, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31876448

RESUMEN

In the present study, specialized methodology of utilizing novel nanobiocatalyst, chitosan coated magnetic graphene (Fe3O4/GO/CS), for efficacious immobilization of Trichoderma reesei cellulase, an important industrial enzyme was revealed. The cellulase was covalently immobilized onto the nanocomposite (NC) using covalent-glutaraldehyde coupling methodology. Successful immobilization of the cellulase with Fe3O4/GO/CS NC was affirmed by transmission electron microscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The nanobiocatalyst preparations exhibited significantly improved activity, retaining 78% of the initial activity as compared to its soluble counterpart. Immobilization of cellulase also highlighted significant broadening in pH, thermal and storage stability profiles. The kinetic properties of cellulase bound Fe3O4/GO/CS NC showed lower Km indicating increased affinity (1.87 times) of nanobioconjugate toward the substrate. Cellulase bound Fe3O4/GO/CS NC was able to maintain higher percentages of its primary activity after 8 repeated uses. This nanobioconjugate preparation proves to be industrially robust biocatalyst with enhanced nano-biocatalytic activity, stability and reusability attributes, which can be exploited for hydrolysis of microcrystalline cellulose providing increased amount of sugar compared to free cellulase.


Asunto(s)
Celulasa/química , Celulosa/química , Enzimas Inmovilizadas/química , Proteínas Fúngicas/química , Nanocompuestos/química , Quitosano/análogos & derivados , Grafito/química , Hidrólisis , Hypocreales/enzimología , Nanopartículas de Magnetita/química
4.
J Nanosci Nanotechnol ; 18(1): 486-499, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29768874

RESUMEN

The enzymes proteases have attracted a lot of attention due to their high demand in various industrial and other sectors since past several decades. Nanosupport bound proteases showed high efficiency of binding and yield of immobilization. Enzymes attached to such support were found significantly more resistant to the denaturation mediated by change in pH and temperature, medium particularly in the presence of water miscible and immiscible organic solvents, detergents, and several kinds of other denaturants. Immobilized enzymes were less inhibited by their own inhibitors compared to their soluble form. Moreover, it has been demonstrated that the attachment of proteases to the nanosize materials prevented them from the problems of steric hindrances during binding of substrate to the active sites of the enzymes as this is frequently occurred when proteases immobilized on the bulk supports. Nanomaterials based immobilized proteases have successfully applied in batch as well as in continuous reactors for the hydrolysis of proteins in detergent and leather industry, pharmaceuticals, food supplements, synthesis of novel peptides and other useful compounds. Nanosupport bound proteases have successfully been used for the analysis of ochratoxins, heavy metals and other bivalents ions, pharmaceutically important compounds and other useful peptides, proteins, including monoclonal antibodies and the bound enzymes have also been used for screening the drugs on the basis of enzyme inhibition assay. Moreover, nanomaterials immobilized protease have shown their high catalytic efficiency in organic solvents and helped in the synthesis of several pharmaceutically and industrially important novel compounds.


Asunto(s)
Proteínas Bacterianas , Péptido Hidrolasas , Estabilidad de Enzimas , Enzimas Inmovilizadas/metabolismo , Hidrólisis , Péptido Hidrolasas/metabolismo , Solventes
5.
Crit Rev Biotechnol ; 37(3): 355-370, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27049593

RESUMEN

Nanocellulose (NC) from cellulosic biomass has recently gained attention owing to their biodegradable nature, low density, high mechanical properties, economic value and renewability. They still suffer, however, some drawbacks. The challenges are the exploration of raw materials, scaling, recovery of chemicals utilized for the production or functionalization and most important is toxic behavior that hinders them from implementing in medical/pharmaceutical field. This review emphasizes the structural behavior of cellulosic biomass and biological barriers for enzyme interactions, which are pertinent to understand the enzymatic hydrolysis of cellulose for the production of NCs. Additionally, the enzymatic catalysis for the modification of solid and NC is discussed. The utility of various classes of enzymes for introducing desired functional groups on the surface of NC has been further examined. Thereafter, a green mechanistic approach is applied for understanding at molecular level.


Asunto(s)
Celulasa/química , Celulosa/química , Celulosa/ultraestructura , Tecnología Química Verde/métodos , Modelos Químicos , Nanopartículas/química , Activación Enzimática , Estabilidad de Enzimas , Hidrólisis , Nanopartículas/ultraestructura , Tamaño de la Partícula , Propiedades de Superficie
6.
Prep Biochem Biotechnol ; 44(6): 558-71, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24499361

RESUMEN

Immobilization of biologically important molecules on a myriad of nanosized materials has attracted great attention due to their small size, biocompatibility, higher surface-to-volume ratio, and lower toxicity. These properties make nanoparticles (NPs) a superior matrix over bulk material for the immobilization of enzymes and proteins. In the present study, Bacillus amyloliquefaciens α-amylase was immobilized on SnO2 nanoparticles by a simple adsorption mechanism. Nanoparticle-adsorbed enzyme retained 90% of the original enzyme activity. Thermal stability of nanosupport was investigated by thermogravimetric and differential thermal analysis. Scanning electron microscopic studies showed that NPs have porous structure for the high-yield immobilization of α-amylase. The genotoxicity of SnO2-NPs was analyzed by pUC(19) plasmid nicking and comet assay and revealed that no remarkable DNA damage occurred in lymphocytes. The pH-optima was found to be the same for both free and SnO2-NPs bound enzyme, while the temperature-optimum for NPs-adsorbed α-amylase was 5°C higher than its free counterpart. Immobilized enzyme retained more than 70% enzyme activity even after its eight repeated uses.


Asunto(s)
Proteínas Bacterianas/química , Enzimas Inmovilizadas , Nanopartículas/química , Compuestos de Estaño/química , alfa-Amilasas/química , Adsorción , Bacillus/química , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/farmacología , Supervivencia Celular/efectos de los fármacos , Ensayo Cometa , Fragmentación del ADN/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno , Cinética , Linfocitos/citología , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Microscopía Electrónica de Rastreo , Nanopartículas/toxicidad , Nanopartículas/ultraestructura , Plásmidos/química , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Compuestos de Estaño/toxicidad , alfa-Amilasas/aislamiento & purificación , alfa-Amilasas/farmacología
7.
Front Med (Lausanne) ; 11: 1425691, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39309679

RESUMEN

Endometriosis is a chronic, estrogen-dependent, proinflammatory disease that can cause various dysfunctions. The main clinical manifestations of endometriosis include chronic pelvic pain and impaired fertility. The disease is characterized by a spectrum of dysfunctions spanning hormonal signaling, inflammation, immune dysregulation, angiogenesis, neurogenic inflammation, epigenetic alterations, and tissue remodeling. Dysregulated hormonal signaling, particularly involving estrogen and progesterone, drives abnormal growth and survival of endometrial-like tissue outside the uterus. Chronic inflammation, marked by immune cell infiltration and inflammatory mediator secretion, perpetuates tissue damage and pain. Altered immune function, impaired ectopic tissue clearance, and dysregulated cytokine production contribute to immune dysregulation. Enhanced angiogenesis promotes lesion growth and survival. Epigenetic modifications influence gene expression patterns, e.g., HSD11B1 gene, affecting disease pathogenesis. Endometriosis related changes and infertility lead to depression in diagnosed women. Depression changes lifestyle and induces physiological and immunological changes. A higher rate of depression and anxiety has been reported in women diagnosed with endometriosis, unleashing physiological, clinical and immune imbalances which further accelerate chronic endometriosis or vice versa. Thus, both endometriosis and depression are concomitantly part of a vicious cycle that enhance disease complications. A multidimensional treatment strategy is needed which can cater for both endometrial disease and depression and anxiety disorders.

8.
Crit Rev Biotechnol ; 33(3): 260-92, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22712546

RESUMEN

Bisphenol A is predominantly used as an intermediate in the production of polycarbonate plastics and epoxy resins. Traces of bisphenol A released into the environment can reach into the wastewater and soil via application of sewage sludge from wastewater treatment systems that receive water containing bisphenol A, or from leachate from uncontrolled landfills. In this study we have made an effort to review the work on the presence of bisphenol A and other related endocrine disrupting compounds in the environment and their impact on the life of living organisms including human beings. Bisphenol A has several implications on the health of human beings as well it can also affect the growth of plants and animals. Number of physicochemical methods such as adsorption, membrane based filtration, ozonation, fenton, electrochemical and photochemical degradation has been used for the removal of bisphenol A. However, these methods have some inherent limitations and therefore cannot be used for large scale treatment of such pollutants. The alternative procedures have attracted the attention of environmental scientists. Biological methods are looking quite promising and these procedures are helpful in the complete degradation of bisphenol A and related compounds. Several bacterial, fungal, and algal strains and mixed cultures have successfully been employed for the degradation of bisphenol A. Recently, enzymatic methods have attracted the attention of the environmentalists for the treatment of bisphenol A and other endocrine disrupting compounds. Numerous types of oxidoreductases; laccases, tyrosinases, manganese peroxidase, lignin peroxidase, polyphenol oxidases, horseradish peroxidase and bitter gourd peroxidase have exhibited their potential for the remediation of such types of compounds. The cytochrome P 450 monooxygenases and hemoglobin have also participated in the degradation of bisphenol A and other related endocrine disrupting compounds. Various redox mediators, surfactants and additives have also enhanced enzymatic oxidation of bisphenol A and other related endocrine disrupting compounds.


Asunto(s)
Compuestos de Bencidrilo/química , Oxidorreductasas/química , Fenoles/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Compuestos de Bencidrilo/aislamiento & purificación , Biodegradación Ambiental , Fenoles/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química
9.
Appl Microbiol Biotechnol ; 97(4): 1513-22, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23011348

RESUMEN

The size distribution of nanomaterials and their similarity in size with enzyme molecules together with other advantageous properties such as thermal stability, high surface-to-volume ratio, and irradiation resistance have revolutionized nanobiocatalytic approaches in various areas of enzyme technology. In the present study, polyaniline-assisted Ag nanocomposites were synthesized using ammonium peroxydisulfate as oxidant. These nanocomposites were used as a support for the covalent conjugation of α-amylase, one of the important industrial enzymes. X-ray diffraction study showed that the crystalline nature of nanocomposites was increased in the presence of Ag nanoparticles. Thermogravimetric and differential thermal analysis revealed that the synthesized nanocomposites retained significantly very high thermal stability. Scanning electron micrograph showed that Ag nanoparticles were homogeneously dispersed in polyaniline film providing large surface area and microenvironment for enzyme loading. Fourier transform infrared spectroscopy confirmed the conjugation of α-amylase to the functionalized nanocomposites. The conjugated α-amylase exhibited better tolerance to variations in the medium pH and temperature compared with the native enzyme. Immobilized α-amylase hydrolyzes starch more efficiently as compared to the free enzyme in batch process.


Asunto(s)
Compuestos de Anilina/química , Bacillus/enzimología , Proteínas Bacterianas/química , Nanopartículas/química , Plata/química , alfa-Amilasas/química , Bacillus/química , Enzimas Inmovilizadas/química , Nanocompuestos/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
10.
J Diabetes Metab Disord ; 21(1): 1003-1009, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35673491

RESUMEN

Purpose: Diabetes mellitus and periodontitis are inflammatory diseases, the severity of inflammation results in the progression and persistence of both the disorders and affects bones. Diabetic complications aggravate in diabetic subjects having periodontitis; similarly, diabetic patients are more prone to developing gingivitis and periodontitis. Periodontal and diabetic inflammation disturbs bone homeostasis, which possibly involves both innate and adaptive immune responses. The pathogenic processes that link the two diseases are the focus of much research and it is likely that upregulated inflammation arising from each condition adversely affects the other. RANKL/OPG pathway plays a prominent role in periodontal and diabetic inflammation and bone resorption. Method: This review article summarises the literature on the link between inflammatory cytokines and the prevalence of disturbed bone homeostasis in diabetic patients with periodontitis. An extensive search was done in PubMed, Scopus, Medline and Google Scholar databases between April 2003 and May 2021. Result: A total of 27 articles, including pilot studies, case-control studies, cross-sectional studies, cohort studies, randomized control trials, longitudinal studies, descriptive studies and experimental studies, were included in our literature review. Conclusion: Since RANKL/OPG are cytokines and have immune responses, regulating these cytokines expression will help control diabetes, periodontitis and bone homeostasis. The growing evidence of bone loss and increased fracture risk in diabetic patients with periodontitis makes it imperative that health professionals carry out planned treatment focusing on monitoring oral health in diabetic patients; bone markers should also be evaluated in patients with chronic periodontitis with an impaired glycemic state.

11.
Nanotechnology ; 22(45): 455708, 2011 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-22020314

RESUMEN

Proteins adsorbed on nanoparticles (NPs) are being used in biotechnology, biosensors and drug delivery. However, understanding the effect of NPs on the structure of proteins is still in a nascent state. In the present paper tin oxide (SnO2) NPs were synthesized by the reaction of SnCl4·5H2O in methanol via the sol-gel method and characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The binding of these SnO2-NPs with α-amylase was investigated by using UV-vis, fluorescence and circular dichroism (CD) spectroscopic techniques. A strong quenching of tryptophan fluorescence intensity in α-amylase was observed due to formation of a ground state complex with SnO2-NPs. Far-UV CD spectra showed that the secondary structure of α-amylase was changed in the presence of NPs. The Michaelis-Menten constant (K(m)), was found to be 26.96 and 28.45 mg ml(-1), while V(max) was 4.173 and 3.116 mg ml(-1) min(-1) for free and NP-bound enzyme, respectively.


Asunto(s)
Bacillus/efectos de los fármacos , Bacillus/enzimología , Proteínas Bacterianas/química , Enzimas Inmovilizadas/química , Nanopartículas del Metal/química , Compuestos de Estaño/farmacología , alfa-Amilasas/química , Análisis de Varianza , Proteínas Bacterianas/metabolismo , Dicroismo Circular , Enzimas Inmovilizadas/metabolismo , Cinética , Modelos Lineales , Microscopía Electrónica de Transmisión , Espectrometría de Fluorescencia , Espectroscopía Infrarroja por Transformada de Fourier , Triptófano , Difracción de Rayos X , alfa-Amilasas/metabolismo
12.
Environ Technol ; 32(1-2): 83-91, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21473271

RESUMEN

Bitter gourd peroxidase entrapped on calcium-alginate-starch beads was employed for the treatment of water, polluted with benzidine, in a batch process as well as in a continuous reactor. The immobilized enzyme had the same pH and temperature optima as the soluble enzyme. The immobilized enzyme could effectively remove more than 70% of benzidine in a stirred batch process after three hours. After its sixth repeated use, the immobilized enzyme was able to oxidatively degrade and polymerize 58% of benzidine. The horizontal bed reactor, containing the peroxidase entrapped on calcium-alginate-starch beads, retained more than 40% benzidine removal efficiency after one month of its continuous operation. The absorption spectra of the treated benzidine exhibited a marked difference in the absorption at various wavelengths, compared with untreated compound. The horizontal bed reactor containing immobilized peroxidase would be significantly successful for the large-scale treatment of water polluted with aromatic compounds.


Asunto(s)
Bencidinas/aislamiento & purificación , Reactores Biológicos , Enzimas Inmovilizadas/metabolismo , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , 1-Propanol , Alginatos/química , Bencidinas/química , Enzimas Inmovilizadas/química , Ácido Glucurónico/química , Ácidos Hexurónicos/química , Concentración de Iones de Hidrógeno , Momordica charantia/enzimología , Octoxinol , Oxidación-Reducción , Polisorbatos , Almidón/química , Temperatura , Factores de Tiempo , Contaminantes Químicos del Agua/química
13.
J Environ Sci (China) ; 23(7): 1135-42, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22125906

RESUMEN

Calcium-alginate pectin entrapped bitter gourd peroxidase (BGP) has been employed for the treatment of disperse dyes: Disperse Brown 1 (DB 1) and Disperse Red 17 (DR 17). Peroxidase alone was unable to decolorize DR 17 and DB 1. However, the investigated dyes were decolorized maximally by BGP in the presence of 0.2 mmol/L redox mediator, violuric acid (VA). A slow decrease in percent decolorization was observed when VA concentration was higher than 0.2 mmol/L which could likely be due to the high reactivity of its aminoxyl radical (> N-O*) intermediate, that might undergo chemical reactions with aromatic amino acid side chains of the enzyme thereby inactivating it. Maximum decolorization of the dyes was observed at pH 3.0 and 40 degrees C within 2 hr of incubation. Immobilized peroxidase decolorized 98% DR 17 and 71% DB 1 using 35 U of BGP in batch process in 90 min. Immobilized enzyme decolorized 85% DR 17 and 51% DB 1 whereas soluble enzyme decolorized DR 17 to 48% and DB 1 to 30% at 60 degrees C. UV-visible spectral analysis was used to evaluate the degradation of these dyes and their toxicity was tested by Allium cepa test. The generally observed higher stability of the bioaffinity bound enzymes against various forms of inactivation may be related to the specific and strong binding of enzyme with bioaffinity support which prevents the unfolding/denaturation of enzyme. Thus entrapped peroxidase was found to be effective in the decolorization of the investigated dyes.


Asunto(s)
Alginatos/química , Momordica charantia/enzimología , Pectinas/química , Peroxidasa/química , Peroxidasa/metabolismo , Colorantes/metabolismo , Ácido Glucurónico/química , Ácidos Hexurónicos/química
14.
J Adv Periodontol Implant Dent ; 13(1): 28-34, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35919913

RESUMEN

Background: This cross-sectional study investigated the bone mineral density (BMD) in type 2 diabetes mellitus (T2DM) subjects with or without chronic periodontitis (CP). Methods: A total of 120 subjects aged 35‒55, divided equally into four groups: i) T2DM with CP, ii) T2DM without CP, iii) CP alone, and iv) healthy patients, were included in this study. Clinical parameters like plaque index (PI), gingival index (GI), and probing pocket depth (PPD) were recorded. All the participants were evaluated for blood sugar levels using glycated hemoglobin (HbA1c) and BMD by Hologic dual-energy x-ray absorptiometry (DEXA) scan. The association of BMD with clinical periodontal parameters and HbA1c in all groups was investigated using linear correlation analysis (r). Results: The mean value of BMD (0.9020±0.0952 g/cm2) was lower in subjects with both T2DM and CP compared to T2DM and CP alone. BMD was weakly correlated with all the clinical periodontal parameters; a positive correlation was observed between BMD and GI in the T2DM and CP group (r=0.405, P=0.026) and the CP group (r=0.324, P=0.081). A weak positive correlation was observed in BMD and HbA1c in the T2DM group (r=0.261, P=0.13), T2DM and CP group (r=0.007, P=0.970), with a negative correlation to HbA1c in the CP group (r= -0.134, P=0.479). Conclusion: Diabetes mellitus impacts clinical periodontal status and bone mass, and the effect is accentuated when chronic periodontitis is present. Based on the present study, BMD is associated with T2DM and CP, but a weak correlation was observed between BMD and HbA1c and clinical periodontal parameters.

15.
Int J Biol Macromol ; 184: 57-67, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34116091

RESUMEN

ß-Galactosidase was immobilized on modified nanosilver reduced graphene oxide (Ag@rGO) nanocomposite prepared by in vitro synthesis using same enzyme. The effectiveness factor, η value of the immobilized enzyme was calculated to be 0.968, suggesting enhancement in enzyme activity after immobilization. The morphological structure of the crosslinked biopolymer was analyzed using electron microscopy and other characterization techniques. The kinetics displayed a decrease in Km value from 0.50 to 0.44 mmol L-1 while there was an increase in Vmax values from 0.031 to 0.039 µmol min-1 mL-1. The immobilized enzyme retained 85% activity after its 10th repeated use. Inhibition constant (Ki) value suggests galactose to be a more potent inhibitor of the enzyme. Despite the inhibitory potential of these hydrolysis products, the immobilized enzyme preparation retained 44.2% activity in the presence of both inhibitory sugars. The as-synthesized nanobiocatalyst was found quite effective in hydrolyzing 89% of lactose from whey. Hence, this nanobiocatalyst can be used in removing lactose from dairy waste, whey before releasing it into the water bodies. Also, the cytotoxicity and genotoxicity of Ag@rGO NC was assessed on human blood lymphocytes using flow cytometry and comet assay, respectively.


Asunto(s)
Grafito/química , Lactosa/química , Plata/química , beta-Galactosidasa/metabolismo , Biocatálisis , Enzimas Inmovilizadas/metabolismo , Humanos , Hidrólisis , Linfocitos/citología , Linfocitos/efectos de los fármacos , Nanopartículas del Metal , Nanocompuestos , Plata/farmacología
16.
Crit Rev Biotechnol ; 30(1): 41-62, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20143935

RESUMEN

Beta galactosidases have been obtained from microorganisms such as fungi, bacteria and yeasts; plants, animals cells, and from recombinant sources. The enzyme has two main applications; the removal of lactose from milk products for lactose intolerant people and the production of galactosylated products. In order to increase their stability, reusability, and use in continuous reactors, these enzymes have been immobilized on both organic and inorganic support via adsorption, covalent attachment, chemical aggregation, microencapsulation, and entrapment. Free and immobilized preparations of beta galactosidases have been exploited in various applications such as industrial, biotechnological, medical, analytical, and in different other applications. beta galactosidase is widely used in food industry to improve sweetness, solubility, flavor, and digestibility of dairy products. Immobilized beta galactosidases are employed for the continuous hydrolysis of lactose from whey and milk in a number of reactors such as hollow fiber reactors, tapered column reactors, packed bed reactors, fluidized bed reactors etc.


Asunto(s)
Biotecnología , beta-Galactosidasa/metabolismo , Enzimas Inmovilizadas/metabolismo , Geografía
17.
Methods Enzymol ; 630: 365-405, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31931994

RESUMEN

Carbon nanotubes (CNTs) based biosensors are recognized to be a next generation building block for ultrasensitive and fast biosensing systems. This article starting with a brief history on CNTs provides an overview on the recent expansion of research in the field of CNT-based biosensors. This is followed by the discussion on structure and properties related to CNTs. Furthermore, the basic and some newly developed synthetic methods of CNTs are summarized. In this chapter, we used polyaniline cobalt multiwalled CNTs to immobilize ß-galactosidase, by adopting both noncovalent and covalent strategies. Herein, the methodologies of both techniques have been discussed in detail. The η (effectiveness factor) values for nanocomposite bound ß-galactosidase by physical adsorption and covalent method were calculated to be 0.93 and 0.97, respectively. The covalently bound ß-galactosidase retained 92% activity even after its 10th successive reuse as compared to the adsorbed enzyme which exhibited only 74% of its initial activity. CNT armored enzymes demonstrated remarkably high catalytic stability at both sides of temperature and pH-optima along with easy recovery from the reaction medium which can be utilized in various biotechnological applications. Lastly, the scientific and technological challenges in the field are discussed at the end of this chapter.


Asunto(s)
Aspergillus oryzae/enzimología , Enzimas Inmovilizadas/química , Nanotubos de Carbono/química , beta-Galactosidasa/química , Compuestos de Anilina/química , Aspergillus oryzae/química , Técnicas Biosensibles , Estabilidad de Enzimas , Nanocompuestos/química
18.
Int J Biol Macromol ; 158: 150-158, 2020 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-32344094

RESUMEN

Functionalized graphene oxide nano-sheets (PAni-Ag-GONC) were prepared and employed as carrier for covalent immobilization of trypsin. This low cost setting, which involves loading of high amount of enzyme on the matrix, displayed significantly enhanced thermo-stability and pH resistance. The nano-composite (NC) bound trypsin preserved 90% of activity whereas native trypsin retained only 44% of activity after 60 days of storage at a temperature of 4°C. Immobilized trypsin conserved 80.5% of activity even after its ten repeated uses. Almond protein hydrolysates prepared by native and conjugated enzyme was investigated for antioxidant activities and found that peptides resulted from NC bound trypsin displayed increase in radical scavenging activity (i.e. around 30% and 37% scavenging activity observed, respectively by native and NC bound trypsin from same concentration of peptides). This strategy provides a new approach for production of potential biopeptides which may be incorporated in drugs and functional food industries applying PAni-Ag-GONC based biocatalysis. CHEMICAL COMPOUNDS: Trichloroacetic acid (PubChem CID: 6421); Tris (hydroxymethyl)aminomethane (PubChem CID: 6503); Glycine (PubChem CID: 750); and 2,2'-diphenyl-1-picrylhydrazyl (PubChem CID: 74358); Nα- Benzoyl-DL-arginine 4-nitroanilide hydrochloride (PubChem CID: 2724371); Ammonium sulphate (PubChem CID: 6097028).

19.
Mater Sci Eng C Mater Biol Appl ; 112: 110883, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32409040

RESUMEN

Candida rugosa lipase (CRL) was treated with surfactants and immobilized onto the novel formulated magnetic graphene anchored silica nanocomposite (Fe3O4/SiO2/Gr NC). For this purpose, the surface of lipase was initially coated with Triton-X 100 and cetyltrimethylammonium bromide surfactants, to stabilize enzyme in its open form and was then adsorbed onto aminated Fe3O4/SiO2/Gr NC. Glutaraldehyde (GA) was then utilized to cross-link the adsorbed lipase onto the NC. The fabricated NC and conjugated lipase was characterized by various techniques such as FT-IR, XRD, TGA, SEM, TEM, CLSM, CD and Fluorescence spectroscopy. The magnetic character of the as-synthesized NC was verified by AGM investigation. CD and fluorescence spectroscopic analysis demonstrated slight structural rearrangements in lipase upon conjugation. The surfactant stabilized immobilized lipase demonstrated significantly enhanced thermostability, tolerance to various metal ions and inhibitors. The immobilization yield obtained owing to lipase interfacial activation by Triton X 100 and CTAB was remarkably enhanced by 6-folds and 3-folds, respectively which were remarkably higher in comparison to free immobilized lipase. The fabricated nanobiocatalysts were employed to synthesise green apple flavour ester, ethyl valerate via esterification reaction. Triton X 100 stabilized immobilized lipase was a better performer in yielding green apple flavour ester, demonstrating about 90% ester yield as compared to 78% yield obtained by CTAB stabilized immobilized lipase preparation. The obtained outcomes suggested that enzyme structure was stabilized by the GA treatment if executed in the absence or in the presence of detergent, and that, in the company of detergent, a conformation of the lipase with the exposed active center to the medium provided an aggrandized catalytic performance.


Asunto(s)
Proteínas Fúngicas/química , Grafito/química , Lipasa/química , Nanocompuestos/química , Dióxido de Silicio/química , Tensoactivos/química , Biocatálisis , Estabilidad de Enzimas , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Equipo Reutilizado , Óxido Ferrosoférrico/química , Proteínas Fúngicas/metabolismo , Cinética , Lipasa/metabolismo , Magnetismo , Saccharomycetales/enzimología
20.
Int J Biol Macromol ; 165(Pt B): 2000-2009, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-33031855

RESUMEN

Peroxidases from Ziziphus mauritiana leaves were immobilized via complexation with gellan gum, followed by crosslinking. The impact of combined complexation-crosslinking approach on the activity and stability of the peroxidases was studied by employing the biocatalyst for the degradation of acid black 1. As compared to free peroxidases, complexed and crosslinked peroxidases displayed significantly higher pH and thermal stability. Immobilized peroxidases showed a 3-fold enhancement in thermal stability upon incubation at 60 °C for 2 h. Immobilized peroxidases retained a promising reusability of about 67% when applied for 8 repeated cycles of acid black 1 decolorization and displayed higher catalytic activity than free enzyme when employed in a stirred batch process. Putative degradation scheme of acid black 1 was proposed with the help of degradation products identified by gas chromatography-mass spectrometry which confirmed the degradation of the dye into smaller molecular weight metabolites. Molecular docking studies of peroxidases with gellan gum revealed the binding site of gellan gum resides far away from the active site of the enzyme.


Asunto(s)
Técnicas de Cultivo Celular por Lotes/métodos , Colorantes/química , Peroxidasas/metabolismo , Polisacáridos Bacterianos/química , Ziziphus/enzimología , Sitios de Unión , Estabilidad de Enzimas , Enzimas Inmovilizadas/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Humanos , Concentración de Iones de Hidrógeno , Cinética , Simulación del Acoplamiento Molecular , Mutágenos/toxicidad , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura
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