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1.
Langmuir ; 38(30): 9294-9300, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35863074

RESUMEN

Oral administration of therapeutic proteins is very challenging because of gastrointestinal instability and decomposition. In this study, we developed a system for oral delivery of superoxide dismutase (SOD) as one of the therapeutic proteins. SOD-loaded capsosomes (SOD-C) were formed by the assembly of chitosan-coated solid lipid nanoparticles and SOD-loaded liposomes (SOD-L). Unlike raw SOD activity decreases to 19.41% in SGF and 13.70% in SIF, the SOD-C in SGF (89.30%) condition retained its initial catalytic activity and decreased but exhibited a three-fold higher raw SOD activity even after incubation in SIF (41.63%). TEM analysis indicated that after intestinal digestion, the residual amount of intact liposomes affected the higher catalytic activity of SOD-C compared to raw SOD and SOD-L. Based on these results, significantly higher cellular uptake of SOD-C was observed compared to raw SOD. Also, SOD-C remarkably suppressed the cellular malondialdehyde (MDA) concentration by maintaining the antioxidative capacity of SOD to remove MDA produced in the oxidative stress-induced cells, thereby contributing to a significant five-fold difference with SOD-R (p < 0.05). This delivery system can facilitate the oral application of other therapeutic proteins, improving gastrointestinal stability.


Asunto(s)
Liposomas , Nanopartículas , Concentración de Iones de Hidrógeno , Superóxido Dismutasa
2.
Appl Microbiol Biotechnol ; 106(12): 4563-4574, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35748913

RESUMEN

The effect of the Escherichia coli (E. coli) Rosetta (DE3) system on the expression of recombinant papain-like cysteine protease inhibitors (SnuCalCpIs) was evaluated, and the inhibition mode of the expressed inhibitor was determined. SnuCalCpI08 and SnuCalCpI17, which previously had not been expressed in the E. coli BL21 (DE3) system due to rare codons of more than 10%, were successfully expressed in E. coli Rosetta (DE3) since the strain provides tRNAs for six rare codons. Initially, both inhibitors were expressed as inclusion bodies; however, the water solubility of SnuCalCpI17 could be improved by lowering the incubation temperature, reducing the IPTG concentration, and increasing the induction time. In contrast, the other inhibitor could not be solubilized in water. To validate whether the inhibitor was expressed with correct protein folding, a papain inhibition assay was performed with SnuCalCpI17. SnuCalCpI17 showed a half-maximal inhibitory concentration (IC50) of 105.671 ± 9.857 µg/mL and a slow-binding inhibition mode against papain at pH 7.0 with a Kiapp of 75.80 µg/mL. The slow-binding inhibitor has a slow dissociation from the inhibitor-target complex, resulting in a long residence time in vivo, and thus can effectively inhibit the target at doses far below the IC50 of the inhibitor. KEY POINTS: • Propeptide inhibitor (SnuCalCpI17) containing rare codons was expressed in E. coli Rosetta (DE3). • The slow-binding inhibition was shown by plotting the apparent first-order rate constant (kobs). • Protein-protein interaction between SnuCalCpIs and papain was verified by docking simulation.


Asunto(s)
Escherichia coli , Papaína , Codón/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Papaína/genética , Papaína/metabolismo , Inhibidores de Proteasas , Proteínas Recombinantes/metabolismo , Agua/metabolismo
3.
Food Microbiol ; 102: 103869, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34809926

RESUMEN

We investigated the synergistic antimicrobial activity of erythorbyl laurate (EL) and mild heating co-treatment on the Gram-positive Listeria innocua and Gram-negative Escherichia coli O157:H7 bacteria. EL (2 mM) and mild heating (55 °C for 3 min) resulted in 3.1 and 0.5 log colony forming units (CFU)/mL reductions in the number of L. innocua, respectively, compared to a 6.4 log CFU/mL reduction induced by the combined treatment of EL and mild heating in saline. EL (10 mM) and mild heating (55 °C for 3 min) resulted in 1.3 and 0.7 log CFU/mL reductions in the number of E. coli O157:H7, respectively, compared to a 6.2 log CFU/mL reduction with the combined treatment in saline. EL, a membrane-active compound, showed a strong synergistic effect with mild heating, possibly due to enhanced disruption of the bacterial cell membrane. The synergistic antibacterial effect was evaluated using inoculated English peas (Pisum sativum) and this combined treatment (2 mM EL and mild heating against L. innocua and 10 mM EL and mild heating against E. coli O157:H7) resulted in more than 7 log reductions in the numbers of L. innocua and E. coli O157:H7, inoculated on the surface of fresh peas. The treatments did not show significant difference in the color or texture of treated peas compared to the non-treated controls. This is the first report illustrating synergistic activity of EL and mild heating for both the gram positive (L. innocua) and the gram negative (E. coli O157:H7) bacteria on food. Overall, this research will illustrate the development of more effective and rapid antibacterial surface disinfection method for application in the processing of minimally processed foods.


Asunto(s)
Antiinfecciosos , Escherichia coli O157 , Manipulación de Alimentos , Lauratos/farmacología , Listeria , Pisum sativum/microbiología , Antiinfecciosos/farmacología , Recuento de Colonia Microbiana , Descontaminación , Microbiología de Alimentos , Calor
4.
Molecules ; 26(7)2021 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-33800606

RESUMEN

We investigated the effect of endogenous cathepsin L on surimi gel produced from olive flounder (Paralichthys olivaceus). The amino acid sequences of six proteins predicted or identified as cathepsin L were obtained from the olive flounder genome database, and a phylogenetic analysis was conducted. Next, cathepsin L activity toward N-α-benzyloxycarbonyl-l-phenylalanyl-l-arginine-(7-amino-4-methylcoumarin) (Z-F-R-AMC) was detected in crude olive flounder extract and a crude enzyme preparation. A considerable decrease in the level of myosin heavy chain (MHC) in surimi occurred during autolysis at 60 °C. In contrast, the levels of actin, troponin-T, and tropomyosin decreased only slightly. To prevent protein degradation by cathepsin L, a protease inhibitor was added to surimi. In the presence of 1.0% protease inhibitor, the autolysis of olive flounder surimi at 60 °C was inhibited by 12.2%; the degree of inhibition increased to 44.2% as the inhibitor concentration increased to 3.0%. In addition, the deformation and hardness of modori gel increased as the inhibitor concentration increased to 2.0%. Therefore, cathepsin L plays an important role in protein degradation in surimi, and the quality of surimi gel could be enhanced by inhibiting its activity.


Asunto(s)
Catepsina L/metabolismo , Proteínas de Peces/metabolismo , Lenguado/metabolismo , Tecnología de Alimentos/métodos , Proteínas Musculares/metabolismo , Actinas/química , Actinas/metabolismo , Secuencia de Aminoácidos , Animales , Catepsina L/antagonistas & inhibidores , Catepsina L/genética , Catepsina L/aislamiento & purificación , Productos Pesqueros/análisis , Proteínas de Peces/antagonistas & inhibidores , Proteínas de Peces/genética , Proteínas de Peces/aislamiento & purificación , Lenguado/clasificación , Lenguado/genética , Expresión Génica , Humanos , Proteínas Musculares/antagonistas & inhibidores , Proteínas Musculares/genética , Proteínas Musculares/aislamiento & purificación , Músculos/química , Músculos/enzimología , Cadenas Pesadas de Miosina/química , Cadenas Pesadas de Miosina/metabolismo , Filogenia , Inhibidores de Proteasas/farmacología , Proteolisis , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Tropomiosina/química , Tropomiosina/metabolismo , Troponina T/química , Troponina T/metabolismo
5.
Molecules ; 24(10)2019 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-31108865

RESUMEN

The objective of this study was to investigate the influence of pH value on the in vitro digestibility of malic acid-treated corn starch in relation to its structural properties. Varying pH values (1.5-8.5) of 2 M malic acid solution were combined with corn starch in a forced-air oven at 130 °C for 12 h. Using Fourier-transform infrared spectroscopy (FT-IR), carbonyl groups were detected in malic acid-treated corn starch, indicating cross-linking through esterification. As the pH value of malic acid-treated corn starch decreased from 8.5 to 1.5, the resistant starch content increased from 18.2 to 74.8%. This was the result of an increased degree of substitution and was maintained after gelatinization. The granular structure of malic acid-treated corn starches was not destroyed, and the starches maintained birefringence. This malic acid-treated corn starch could be utilized in heat processed foods such as bread and cookies as well as in products with reduced calories.


Asunto(s)
Malatos/química , Almidón/química , Zea mays/química , Concentración de Iones de Hidrógeno , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
6.
Soft Matter ; 14(14): 2586-2593, 2018 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-29442124

RESUMEN

Many research groups have developed unique micro/nano-structured dry adhesives by mimicking the foot of the gecko with the use of molding methods. Through these previous works, polydimethylsiloxane (PDMS) has been developed and become the most commonly used material for making artificial dry adhesives. The material properties of PDMS are well suited for making dry adhesives, such as conformal contacts with almost zero preload, low elastic moduli for stickiness, and easy cleaning with low surface energy. From a performance point of view, dry adhesives made with PDMS can be highly advantageous but are limited by its low productivity, as production takes an average of approximately two hours. Given the low productivity of PDMS, some research groups have developed dry adhesives using UV-curable materials, which are capable of continuous roll-to-roll production processes. However, UV-curable materials were too rigid to produce good adhesion. Thus, we established a PDMS continuous-production system to achieve good productivity and adhesion performance. We designed a thermal roll-imprinting lithography (TRL) system for the continuous production of PDMS microstructures by shortening the curing time by controlling the curing temperature (the production speed is up to 150 mm min-1). Dry adhesives composed of PDMS were fabricated continuously via the TRL system.

7.
Analyst ; 143(19): 4623-4629, 2018 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-30207329

RESUMEN

We developed a paper-based analytical device (µPAD) combined with self-signaling polydiacetylene (PDA) liposomes for convenient visual neomycin detection. The simple dot array type of µPAD was fabricated by the wax printing technique, and the PDA liposomes in the aqueous solution were facilely immobilized onto the hydrophilic dot region of the paper substrate. We found that, when the PDA liposomes were inserted to the paper matrix, the stability of the PDA liposomes can be significantly enhanced by adding a hydrophilic reagent such as polyvinyl alcohol and glycerol to the liposome solution. In particular, polyvinyl alcohol (PVA) provides the best stabilization among the various hydrophilic reagents tested in this contribution, and the enhanced stability sharply increased the sensitivity of the PDA liposomes in the paper matrix. Based on the above results, we successfully detected neomycin through both naked-eye observation and fluorescence measurement of PDA signals. The detection limit was 1 ppm and was selective to non-aminoglycoside antibiotics.


Asunto(s)
Técnicas Biosensibles , Colorimetría , Liposomas , Neomicina/análisis , Polímeros , Poliinos , Límite de Detección , Polímero Poliacetilénico
8.
J Enzyme Inhib Med Chem ; 33(1): 657-664, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29560748

RESUMEN

Cathepsin L of cancer cells has been shown to play an important role in degradation of extracellular matrix for metastasis. In order to reduce cell invasion, cathepsin L propeptide-like proteins which are classified as the I29 family in the MEROPS peptidase database were characterized from Calotropis procera R. Br., rich in cysteine protease. Of 19 candidates, the cloned and expressed recombinant SnuCalCp03-propeptide (rSnuCalCp03-propeptide) showed a low nanomolar Ki value of 2.3 ± 0.2 nM against cathepsin L. A significant inhibition of tumor cell invasion was observed with H1975, HT29, MDA-BM-231, PANC1, and PC3 with a 76, 67, 67, 63, and 79% reduction, respectively, in invasion observed in the presence of 400 nM of the rSnuCalCp03-propeptide. In addition, thermal and pH study showed rSnuCalCp03-propeptide consisting of secondary structures was stable at a broad range of temperatures (30-70 °C) and pH (2-10, except for 5 which is close to the isoelectric point of 5.2).


Asunto(s)
Calotropis/química , Catepsina L/metabolismo , Clonación Molecular , Precursores Enzimáticos/metabolismo , Catepsina L/química , Catepsina L/genética , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Precursores Enzimáticos/química , Precursores Enzimáticos/genética , Humanos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Relación Estructura-Actividad
9.
Sensors (Basel) ; 18(1)2018 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-29303979

RESUMEN

An immobilized liposome electrode (ILE)-based sensor was developed to quantify conformational changes of the proteins under various stress conditions. The ILE surface was characterized by using a tapping-mode atomic force microscopy (TM-AFM) to confirm surface immobilization of liposome. The uniform layer of liposome was formed on the electrode. The current deviations generated based on the status of the proteins under different stress were then measured. Bovine carbonic anhydrase (CAB) and lysozyme were tested with three different conditions: native, reduced and partially denatured. For both proteins, a linear dynamic range formed between denatured concentrations and output electric current signals was able to quantify conformational changes of the proteins. The pattern recognition (PARC) technique was integrated with ILE-based sensor to perform data analysis and provided an effective method to improve the prediction of protein structural changes. The ILE-based stress sensor showed potential of leveraging the amperometric technique to manifest activity of proteins based on various external conditions.


Asunto(s)
Liposomas/química , Animales , Bovinos , Electrodos , Microscopía de Fuerza Atómica , Proteínas
10.
J Microencapsul ; 32(5): 503-10, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26079598

RESUMEN

To develop a novel self-nanoemulsifying drug delivery system (solid SNEDDS) with better oral bioavailability of tacrolimus, the solid SNEDDS was obtained by spray-drying the solutions containing the liquid SNEDDS and colloidal silica. Its reconstitution properties were determined and correlated to solid state characterisation of the powder. Moreover, the dissolution and pharmacokinetics in rats was done in comparison to the commercial product. Among the liquid SNEDDS formulations tested, the liquid SNEDDS comprised of Capryol PGMC, Transcutol HP and Labrasol (10:15:75, v/v/v) presented the highest dissolution rate. In the solid SNEDDS, this liquid SNEDDS was absorbed in the pores and attached onto the surface of the colloidal silica. Drug was present in the amorphous state in it. The solid SNEDDS with 5% w/v tacrolimus produced the nanoemulsions and improved the oral bioavailability of tacrolimus in rats. Therefore, this solid SNEDDS would be a potential candidate for enhancing the oral bioavailability of tacrolimus.


Asunto(s)
Portadores de Fármacos , Tacrolimus , Administración Oral , Animales , Disponibilidad Biológica , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Emulsiones , Ratas , Solubilidad , Tacrolimus/química , Tacrolimus/farmacocinética
11.
Appl Environ Microbiol ; 80(3): 1020-5, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24271177

RESUMEN

A new medium (lecithin and levofloxacin [LL] medium) is described for the isolation of Listeria monocytogenes from food samples. LL medium includes lecithin from soybeans for the detection of phosphatidylinositol-specific phospholipase C (PI-PLC) and phosphatidylcholine-specific phospholipase C (PC-PLC) produced by L. monocytogenes. Levofloxacin is incorporated to inhibit the growth of microorganisms other than L. monocytogenes, especially Bacillus cereus, shown to possess PI-PLC and PC-PLC activities. L. monocyogenes produced white colonies with a halo on LL medium, whereas Listeria innocua appeared as white colonies without a halo. Levofloxacin at 0.20 mg/liter completely inhibited the growth of B. cereus, while the growth of L. monocytogenes was unaffected. In the second phase of the study, the sensitivity and the specificity of LL medium were compared to those of modified Oxford agar (MOX) and two chromogenic media (Brilliance Listeria agar and CHROMagar Listeria), using a total of 250 food samples. From 200 unspiked food samples, the specificity of LL medium (96.0%) was superior to that of MOX (72.0%) and similar to the specificities of Brilliance Listeria agar (96.5%) and CHROMagar Listeria (94.5%). From 50 spiked food samples, LL medium and CHROMagar Listeria represented the highest sensitivities (96.0%), followed by Brilliance Listeria agar (92.0%) and MOX (54.0%). Also, LL medium showed the highest confirmation rate (98.8%), followed by Brilliance Listeria agar (98.7%), CHROMagar Listeria (98.3%), and MOX (52.0%). On the basis of its good specificity and cost effectiveness, LL medium is useful for the isolation of L. monocytogenes from food samples.


Asunto(s)
Medios de Cultivo/química , Microbiología de Alimentos/métodos , Listeria monocytogenes/aislamiento & purificación , Antibacterianos/farmacología , Lecitinas/metabolismo , Levofloxacino/farmacología , Listeria monocytogenes/enzimología , Listeria monocytogenes/crecimiento & desarrollo , Selección Genética , Sensibilidad y Especificidad , Fosfolipasas de Tipo C/análisis
12.
Int J Biol Macromol ; 276(Pt 2): 134013, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39032883

RESUMEN

Lipase with unique regioselectivity is an attractive biocatalyst for elaborate lipid modification. However, the excavation of novel sn-2 regioselective lipases is difficult due to their scarcity in nature, with Candida antarctica lipase A (CALA) being the pronouncedly reported one. Here, we identified a novel CALA-like lipase from Cordyceps militaris (CACML7) via in silico mining. Through chiral-phase high-performance liquid chromatography, we determined that CACML7 displays sn-2 regioselectivity (>68 %) as does CALA, but exhibits distinctive chain length selectivity and bias against unsaturated fats. Notably, the curvature of the acyl-binding tunnel was expected to contribute to the 2.2-fold higher preference for cis-fatty acid (C18:1, cis-Δ9) over trans-fatty acid (C18:1, trans-Δ9) unlike trans-active CALA. Random pose docking of trioleoylglycerol (TOG) into the active site of a lid-truncated mutant of CACML7 revealed that TOG accepts a tuning fork conformation, of which the precise positioning of the reactive ester group towards the catalytic center was only favorable via sn-2 binding mode. The unique active site morphology, which we refer to as an "acyl-binding tunnel with a narrow entrance," may contribute to the sn-2 regioselectivity of CACML7. Our data provide an attractive model to better understand the mechanism underlying sn-2 regioselectivity.

13.
Food Chem ; 451: 139437, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38678653

RESUMEN

This study explores the potential for optimizing a sustainable manufacturing process that maintains the essential characteristics of conventional liposomes using food-grade solvents and components. The focus was comparing the physicochemical, morphological, and interfacial properties of liposomes produced with these food-grade ingredients to those made by conventional methods. It was found that there was no significant difference in particle size (195.87 ± 1.40 nm) and ζ-potential (-45.13 ± 0.65 mV) between liposomes made from food-grade and conventional materials. The manufacturing process for liposomes, utilizing food-grade solvents and components, was optimized through the application of Plackett-Burman design and response surface methodology. This approach helped identify key parameters (soy lecithin, ß-sitosterol, W/O ratio) and their optimal values (3.17 g, 0.25 g, 1:2.59). These findings suggest that it is possible to enhance the use of liposomes as an effective and safe delivery system in the food industry, adhering to the strict guidelines set by regulatory agencies.


Asunto(s)
Lecitinas , Liposomas , Tamaño de la Partícula , Liposomas/química , Lecitinas/química , Sitoesteroles/química , Microfluídica/instrumentación , Glycine max/química
14.
Sensors (Basel) ; 13(3): 2818-29, 2013 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-23447013

RESUMEN

Static headspace gas chromatographic (SHS-GC) analysis was performed to determine the release of 13 odorants in hydrocolloid model systems containing original or regio-selectively carboxylated cellulose at different pH values. The release of most odor compounds was decreased in the hydrocolloid solutions compared to control, with the amounts of 2-propanol, 3-methyl-1-butanol, and 2,3-butanedione released into the headspace being less than those of any other odor compound in the hydrocolloid model systems. However, there was no considerable difference between original cellulose-containing and carboxylated-cellulose containing systems in the release of most compounds, except for relatively long-chain esters such as ethyl caprylate and ethyl nonanoate. The release from the original and carboxylated cellulose solutions controlled to pH 10 was significantly higher than that from solutions adjusted to pH 4 and 7 in the case of some esters (ethyl acetate, methyl propionate, ethyl propionate, ethyl butyrate, butyl propionate, ethyl caproate) and alcohols (2-propanol, 3-methyl-1-butanol), in particular, ethyl butyrate and 3-methyl-1-butanol. In contrast, the release of 2,3-butanedione from both the original and carboxylated cellulose solutions was increased at pH 4 and 7 compared to that at pH 10 by about 70% and 130%, respectively. Our study demonstrated that the release of some odorants could be changed significantly by addition of both original and carboxylated cellulose in hydrocolloid model systems, but only minor effect was observed in pH of the solution.


Asunto(s)
Celulosa/química , Coloides/química , Odorantes/análisis , 2-Propanol/análisis , 2-Propanol/aislamiento & purificación , Ácidos Carboxílicos/química , Cromatografía de Gases , Diacetil/aislamiento & purificación , Ésteres/aislamiento & purificación , Concentración de Iones de Hidrógeno , Pentanoles/aislamiento & purificación
15.
Food Chem ; 399: 133949, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-35998496

RESUMEN

This study demonstrated that solvent-free gas bubbling system enhanced production efficiency of pyridoxine monolaurate in the esterification catalyzed by immobilized Candida antarctica lipase B (Lipozyme 435). Volumetric productivity in solvent-free gas bubbling system (41.24 mmol/L/h) was 3.7 and 2.1-fold higher than those in conventional organic solvent system (11.10 mmol/L/h) and solvent-free system (19.86 mmol/L/h) using magnetic stirring, respectively. Among the three bioreactor systems, solvent-free gas bubbling system provided the best reusability of the lipase retaining 94.45 % of initial activity for six batch reactions. In the bioreactor system, 5-O-lauroyl-pyridoxine was regioselectively produced with maximum production of 371.17 mmol/L at 70 °C and 0.10 of substrate molar ratio ([pyridoxine]/[lauric acid]) for 9 h. Pyridoxine monolaurate exhibited interfacial activity at oil-water interfaces, suggesting it had emulsifying properties. Pyridoxine monolaurate is expected to be applied as a multi-functional emulsifier with nutritional values to replace both small molecule emulsifiers and pyridoxine hydrochloride in fortified beverages.


Asunto(s)
Enzimas Inmovilizadas , Piridoxina , Reactores Biológicos , Catálisis , Enzimas Inmovilizadas/química , Esterificación , Lipasa/metabolismo , Solventes/química
16.
Food Chem ; 404(Pt B): 134697, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36323037

RESUMEN

Erythorbyl ricinoleate (ERO) was synthesized as a novel multi-functional emulsifier with antibacterial and antioxidative activities via lipase-catalyzed esterification between erythorbic acid and ricinoleic acid. Esterification regioselectively produced ERO (6-O-ricinoleoyl-erythorbate) of 238.67 mM at 48 h. ERO effectively reduced interfacial tension to 2.66 mN/m at its critical micelle concentration (0.73 mM), compared with other erythorbyl fatty acid esters (EFEs). Oil-in-water (O/W) emulsion stabilized by ERO remained stable for 15 days with a droplet size of 256.3 nm and polydispersity index of 0.22, whereas the emulsion stabilized by the other EFEs became unstable within six days. ERO had antibacterial activity against Gram-positive bacteria with minimum inhibitory concentrations from 0.2 to 0.6 mM. In O/W emulsion, ERO exhibited higher antioxidative activity than erythorbic acid against lipid oxidation. These findings suggest that ERO has high potential as multi-functional food additive to control lipid oxidation and bacterial contamination for O/W emulsion foods.


Asunto(s)
Antioxidantes , Lipasa , Antioxidantes/farmacología , Emulsiones , Emulsionantes , Antibacterianos/farmacología , Catálisis , Agua
17.
Enzyme Microb Technol ; 168: 110254, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37201411

RESUMEN

Multiple sequence alignments of three lipase isoforms from the filamentous fungus, Cordyceps militaris, have revealed that the deduced protein from their common sequence belongs to the Candida rugosa lipase-like group. To express the protein in its active form, recombinant lipase from C. militaris (rCML) was extra cellularly expressed in Pichia pastoris X-33 after removing its signal peptide. Purified rCML was a stable monomeric protein with a molecular mass of 90 kDa, and was highly N-mannosylated compared to the native protein (69 kDa). The catalytic efficiency (kcat/Km) of rCML was greater than the native protein (1244.35 ± 50.88 and 1067.17 ± 29.07 mM-1·min-1, respectively), yet they had similar optimal pH values and temperatures (40 °C and pH 7.0-7.5), and showed preferences for Tween esters and short-chain triacylglycerols. Despite its monomeric conformation, interfacial activation was not observed for rCML, unlike the classical lipases. From the structural model of rCML, the binding pocket of rCML was predicted as a funnel-like structure consisting of a hollow space and an intramolecular tunnel, which is typical of C. rugosa lipase-like lipases. However, a blockage shortened the tunnel to 12-15 Å, which endows strict short-chain selectivity towards triacylglycerols and a perfect match for tricaproin (C6:0). The limited depth of the tunnel may enable accommodation of triacylglycerols with medium-to-long-chain fatty acids, which differentiates rCML from other C. rugosa lipase-like lipases with broad substrate specificities.


Asunto(s)
Cordyceps , Lipasa , Lipasa/genética , Lipasa/química , Proteínas Recombinantes/química , Pichia/genética , Pichia/metabolismo , Triglicéridos/metabolismo , Especificidad por Sustrato
18.
Food Chem ; 404(Pt A): 134618, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36444044

RESUMEN

Cytochrome c-type cis/trans fatty acid isomerase (CTI) is a promising candidate for directly controlling cis/trans fatty acid isomerism in lipids-related food products like partially hydrogenated vegetable oils. In this study, to establish a sophisticated analysis platform for the CTI assay, we constructed the reversed micelle reaction system and improved the processes of methylation and GC-FID analysis of C18:1cis/trans monounsaturated fatty acid (MUFA) isomers. Highly stable AOT/isooctane reversed micelles were formed in the presence of periplasmic fractions of Pseudomonas putida KT2440. Using a mid-content cyanopropyl phase DB-FastFAME column, C18:1cis/trans-MUFAs were analyzed rapidly and resolved with resolution factors over 1.34. Based on the newly established assay, the catalytic activity of the periplasmic fraction was precisely determined, and its kinetic parameters (Vmax and Km) were derived as 0.021 mM·min-1 and 0.68 mM, respectively. The following results can provide practical information for investigating CTIs in the fields of food and lipid chemistry.


Asunto(s)
Ácidos Grasos Monoinsaturados , Ácidos Grasos trans , Isomerismo , Ácidos Grasos , Bioensayo , Micelas
19.
Carbohydr Polym ; 309: 120646, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-36906355

RESUMEN

Glycogen-like particles (GLPs) are applied in food, pharmaceutical, and cosmetics. The large-scale production of GLPs is limited by their complicated multi-step enzymic processes. In this study, GLPs were produced in a one-pot dual-enzyme system using Bifidobacterium thermophilum branching enzyme (BtBE) and Neisseria polysaccharea amylosucrase (NpAS). BtBE showed excellent thermal stability (half-life of 1732.9 h at 50 °C). Substrate concentration was the most influential factor during GLPs production in this system: GLPs yield and [sucrose]ini decreased from 42.4 % to 17.4 % and 0.3 to 1.0 M, respectively. Molecular weight and apparent density of GLPs decreased significantly with increasing [sucrose]ini. Regardless of the [sucrose]ini, the DP 6 of branch chain length was predominantly occupied. GLP digestibility increased with increasing [sucrose]ini, indicating that the degree of GLP hydrolysis may be negatively related to its apparent density. This one-pot biosynthesis of GLPs using a dual-enzyme system could be useful for the development of industrial processes.


Asunto(s)
Enzima Ramificadora de 1,4-alfa-Glucano , Glucanos , Sacarosa/química , Glucosiltransferasas/química , Bifidobacterium , Neisseria
20.
Sci Rep ; 13(1): 4728, 2023 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-36959258

RESUMEN

Controlling the sizes of liposomes is critical in drug delivery systems because it directly influences their cellular uptake, transportation, and accumulation behavior. Although hydrodynamic focusing has frequently been employed when synthesizing nano-sized liposomes, little is known regarding how flow characteristics determine liposome formation. Here, various sizes of homogeneous liposomes (50-400 nm) were prepared according to flow rate ratios in two solvents, ethanol, and isopropyl alcohol (IPA). Relatively small liposomes formed in ethanol due to its low viscosity and high diffusivity, whereas larger, more poly-dispersed liposomes formed when using IPA as a solvent. This difference was investigated via numerical simulations using the characteristic time factor to predict the liposome size; this approach was also used to examine the flow characteristics inside the microfluidic channel. In case of the liposomes, the membrane rigidity also has a critical role in determining their size. The increased viscosity and packing density of the membrane by addition of cholesterol confirmed by fluorescence anisotropy and polarity lead to increase in liposome size (40-530 nm). However, the interposition of short-chain lipids de-aligned the bilayer membrane, leading to its degradation; this decreased the liposome size. Adding short-chain lipids linearly decreased the liposome size (130-230 nm), but at a shallower gradient than that of cholesterol. This analytical study expands the understanding of microfluidic environment in the liposome synthesis by offering design parameters and their relation to the size of liposomes.


Asunto(s)
Etanol , Liposomas , Solventes , Colesterol , Lípidos , Tamaño de la Partícula
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