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1.
J Sep Sci ; 47(13): e2400154, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38948935

RESUMEN

Glycosylation and phosphorylation rank as paramount post-translational modifications, and their analysis heavily relies on enrichment techniques. In this work, a facile approach was developed for the one-step simultaneous enrichment and stepwise elution of glycoproteins and phosphoproteins. The core of this approach was the application of the novel titanium (IV) ion immobilized poly(glycidyl methacrylate) microparticles functionalized with dendrimer polyethylenimine and phytic acid. The microparticles possessed dual enrichment capabilities due to their abundant titanium ions and hydroxyl groups on the surface. They demonstrate rapid adsorption equilibrium (within 30 min) and exceptional adsorption capacity for ß-casein (1107.7 mg/g) and horseradish peroxidase (438.6 mg/g), surpassing that of bovine serum albumin (91.7 mg/g). Furthermore, sodium dodecyl sulfate-polyacrylamide gel electrophoresis was conducted to validate the enrichment capability. Experimental results across various biological samples, including standard protein mixtures, non-fat milk, and human serum, demonstrated the remarkable ability of these microparticles to enrich low-abundance glycoproteins and phosphoproteins from biological samples.


Asunto(s)
Dendrímeros , Glicoproteínas , Fosfoproteínas , Polietileneimina , Ácidos Polimetacrílicos , Titanio , Glicoproteínas/química , Fosfoproteínas/química , Polietileneimina/química , Dendrímeros/química , Humanos , Titanio/química , Ácidos Polimetacrílicos/química , Interacciones Hidrofóbicas e Hidrofílicas , Propiedades de Superficie , Animales , Tamaño de la Partícula , Adsorción , Bovinos
2.
J Food Sci ; 89(7): 4109-4122, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38957103

RESUMEN

The elucidation of the interaction mechanism between phospholipids and milk proteins within emulsions is pivotal for comprehending the properties of infant formula fat globules. In this study, multispectral methods and molecular docking were employed to explore the relationship between phosphatidylcholine (PC) and whey protein isolate (WPI). Observations indicate that the binding constant, alongside thermodynamic parameters, diminishes as temperature ascends, hinting at a predominantly static quenching mechanism. Predominantly, van der Waals forces and hydrogen bonds constitute the core interactions between WPI and PC. This assertion is further substantiated by Fourier transform infrared spectroscopy, which verifies PC's influence on WPI's secondary structure. A detailed assessment of thermodynamic parameters coupled with molecular docking reveals that PC predominantly adheres to specific sites within α-lactalbumin, ß-lactoglobulin, and bovine serum albumin, propelled by a synergy of hydrophobic interactions, hydrogen bonding, and van der Waals forces, with binding energies noted at -5.59, -6.71, and -7.85 kcal/mol, respectively. An increment in PC concentration is observed to amplify the emulsification properties of WPI whilst concurrently diminishing the zeta potential. This study establishes a theoretical foundation for applying the PC-WPI interaction mechanism in food.


Asunto(s)
Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Simulación del Acoplamiento Molecular , Fosfatidilcolinas , Termodinámica , Proteína de Suero de Leche , Proteína de Suero de Leche/química , Fosfatidilcolinas/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Emulsiones/química , Lactalbúmina/química , Lactalbúmina/metabolismo , Albúmina Sérica Bovina/química , Fórmulas Infantiles/química
3.
Anal Chim Acta ; 1316: 342811, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-38969401

RESUMEN

BACKGROUND: Lipids such as phosphatidic acids (PAs) and cardiolipins (CLs) present strongly tailing peaks in reversed phase liquid chromatography, which entails low detectability. They are usually analyzed by hydrophilic interaction liquid chromatography (HILIC), which hampers high-throughput lipidomics. Thus, there is a great need for improved analytical methods in order to obtain a broader coverage of the lipidome in a single chromatographic method. We investigated the effect of ammonium bicarbonate (ABC) on peak asymmetry and detectability, in comparison with ammonium formate (AFO) on both a conventional BEH C18 column and an HST-CSH C18 column. RESULTS: The combination of 2.5 mM ABC buffer pH 8 with an HST-CSH C18 column produced significantly improved results, reducing the asymmetry factor at 10 % peak height of PA 16:0/18:1 from 8.4 to 1.6. Furthermore, on average, there was up to a 54-fold enhancement in the peak height of its [M - H]- ion compared to AFO and the BEH C18 column. We confirmed this beneficial effect on other strongly tailing lipids, with accessible phosphate moieties e.g., cardiolipins, phosphatidylinositol phosphate, phosphatidylinositol bisphosphate, phosphorylated ceramide and phosphorylated sphingosine. Furthermore, we found an increased detectability of phospho- and sphingolipids up to 28 times in negative mode when using an HST-CSH C18 column. The method was successfully applied to mouse liver samples, where previously undetected endogenous phospholipids could be analyzed with improved chromatographic separation. SIGNIFICANCE: In conclusion, the use of 2.5 mM ABC substantially improved the peak shape of PAs and enhanced the detectability of the lipidome in negative mode on an RPLC-ESI-Q-TOF-MS system on both BEH C18 and HST-CSH C18 columns. This method provides a wider coverage of the lipidome with one single injection for future lipidomic applications in negative mode.


Asunto(s)
Bicarbonatos , Animales , Ratones , Tampones (Química) , Bicarbonatos/química , Lípidos/química , Cromatografía de Fase Inversa/métodos , Propiedades de Superficie , Lipidómica/métodos , Ratones Endogámicos C57BL , Interacciones Hidrofóbicas e Hidrofílicas , Ácidos Fosfatidicos/química , Hígado/química
4.
Chem Biol Drug Des ; 104(1): e14576, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38969623

RESUMEN

Intestinal absorption of compounds is significant in drug research and development. To evaluate this efficiently, a method combining mathematical modeling and molecular simulation was proposed, from the perspective of molecular structure. Based on the quantitative structure-property relationship study, the model between molecular structure and their apparent permeability coefficients was successfully constructed and verified, predicting intestinal absorption of drugs and interpreting decisive structural factors, such as AlogP98, Hydrogen bond donor and Ellipsoidal volume. The molecules with strong lipophilicity, less hydrogen bond donors and receptors, and small molecular volume are more easily absorbed. Then, the molecular dynamics simulation and molecular docking were utilized to study the mechanism of differences in intestinal absorption of drugs and investigate the role of molecular structure. Results indicated that molecules with strong lipophilicity and small volume interacted with the membrane at a lower energy and were easier to penetrate the membrane. Likewise, they had weaker interaction with P-glycoprotein and were easier to escape from it and harder to export from the body. More in, less out, is the main reason these molecules absorb well.


Asunto(s)
Enlace de Hidrógeno , Absorción Intestinal , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Relación Estructura-Actividad Cuantitativa , Humanos , Estructura Molecular , Preparaciones Farmacéuticas/metabolismo , Preparaciones Farmacéuticas/química , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/química , Interacciones Hidrofóbicas e Hidrofílicas , Permeabilidad
5.
Sci Adv ; 10(27): eadn6606, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38959312

RESUMEN

Ice-nucleating proteins (INpro) trigger the freezing of supercooled water droplets relevant to atmospheric, biological, and technological applications. The high ice nucleation activity of INpro isolated from the bacteria Pseudomonas syringae could be linked to the aggregation of proteins at the bacterial membrane or at the air-water interface (AWI) of droplets. Here, we imaged freezing onsets, providing direct evidence of these proposed mechanisms. High-speed cryo-microscopy identified the onset location of freezing in droplets between two protein-repellent glass slides. INpro from sterilized P. syringae (Snomax) statistically favored nucleation at the AWI of the droplets. Removing cellular fragments by filtration or adding surfactants increased the frequency of nucleation events at the AWI. On the other hand, cultivated intact bacteria cells or lipid-free droplets nucleated ice without an affinity to the AWI. Overall, we provide visual evidence that INpro from P. syringae trigger freezing at hydrophobic interfaces, such as the AWI or the bacterial membrane, with important mechanistic implications for applications of INpro.


Asunto(s)
Congelación , Interacciones Hidrofóbicas e Hidrofílicas , Pseudomonas syringae , Pseudomonas syringae/metabolismo , Pseudomonas syringae/química , Proteínas de la Membrana Bacteriana Externa/química , Proteínas de la Membrana Bacteriana Externa/metabolismo , Hielo , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo
6.
Se Pu ; 42(7): 721-729, 2024 Jul.
Artículo en Chino | MEDLINE | ID: mdl-38966980

RESUMEN

Lysine (K) is widely used in the design of lysine-targeted crosslinkers, structural elucidation of protein complexes, and analysis of protein-protein interactions. In "shotgun" proteomics, which is based on liquid chromatography-tandem mass spectrometry (LC-MS/MS), proteins from complex samples are enzymatically digested, generating thousands of peptides and presenting significant challenges for the direct analysis of K-containing peptides. In view of the lack of effective methods for the enrichment of K-containing peptides, this work developed a method which based on a hydrophobic-tag-labeling reagent C10-S-S-NHS and reversed-phase chromatography (termed as HYTARP) to achieve the efficient enrichment and identification of K-containing peptides from complex samples. The C10-S-S-NHS synthesized in this work successfully labeled standard peptides containing various numbers of K and the labeling efficiency achieved up to 96% for HeLa cell protein tryptic digests. By investigating the retention behavior of these labeled peptides in C18 RP column, we found that most K-labeled peptides were eluted once when acetonitrile percentage reached 57.6% (v/v). Further optimization of the elution gradient enabled the efficient separation and enrichment of the K-labeled peptides in HeLa digests via a stepwise elution gradient. The K-labeled peptides accounted for 90% in the enriched peptides, representing an improvement of 35% compared with the number of peptides without the enrichment. The dynamic range of proteins quantified from the enriched K-containing peptides spans 5-6 orders of magnitude, and realized the detection of low-abundance proteins in the complex sample. In summary, the HYTARP strategy offers a straightforward and effective approach for reducing sample complexity and improving the identification coverage of K-containing peptides and low-abundance proteins.


Asunto(s)
Cromatografía de Fase Inversa , Interacciones Hidrofóbicas e Hidrofílicas , Lisina , Péptidos , Cromatografía de Fase Inversa/métodos , Lisina/química , Péptidos/química , Péptidos/análisis , Humanos , Células HeLa , Espectrometría de Masas en Tándem/métodos , Proteómica/métodos
7.
Nat Commun ; 15(1): 5619, 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38965213

RESUMEN

The sigma-1 receptor (σ1R) is a non-opioid membrane receptor, which responds to a diverse array of synthetic ligands to exert various pharmacological effects. Meanwhile, candidates for endogenous ligands of σ1R have also been identified. However, how endogenous ligands bind to σ1R remains unknown. Here, we present crystal structures of σ1R from Xenopus laevis (xlσ1R) bound to two endogenous neurosteroid ligands, progesterone (a putative antagonist) and dehydroepiandrosterone sulfate (DHEAS) (a putative agonist), at 2.15-3.09 Å resolutions. Both neurosteroids bind to a similar location in xlσ1R mainly through hydrophobic interactions, but surprisingly, with opposite binding orientations. DHEAS also forms hydrogen bonds with xlσ1R, whereas progesterone interacts indirectly with the receptor through water molecules near the binding site. Binding analyses are consistent with the xlσ1R-neurosteroid complex structures. Furthermore, molecular dynamics simulations and structural data reveal a potential water entry pathway. Our results provide insight into binding of two endogenous neurosteroid ligands to σ1R.


Asunto(s)
Sulfato de Deshidroepiandrosterona , Simulación de Dinámica Molecular , Progesterona , Receptores sigma , Receptor Sigma-1 , Xenopus laevis , Receptores sigma/metabolismo , Receptores sigma/química , Animales , Ligandos , Sitios de Unión , Progesterona/metabolismo , Progesterona/química , Sulfato de Deshidroepiandrosterona/metabolismo , Sulfato de Deshidroepiandrosterona/química , Unión Proteica , Cristalografía por Rayos X , Neuroesteroides/metabolismo , Neuroesteroides/química , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas
8.
Sci Rep ; 14(1): 15565, 2024 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-38971851

RESUMEN

Lactic acid bacteria (LAB) isolated from medicinal herb Murraya koenigii, commonly known as curry leaf, which promotes the growth and maintenance of gut microbiota, were studied for their probiotic potential. The key objective of this research was to isolate and evaluate probiotic characteristics, test adherence capabilities, and confirm their safety. Lactococcus lactis (MKL8), isolated from Murraya koenigii, was subjected to in vitro analysis to assess its resistance to the gastric environment, ability to adhere Caco-2 cells, anti-microbial activity, hydrophobicity, auto-aggregation, and safety profiling through MTT assay and hemolytic. MKL8 exhibited growth at 0.5% phenol concentrations (> 80%) and was able to survive in conditions with high bile concentrations (> 79%) and a relatively low pH (72%-91%). It shows high tolerance to high osmotic conditions (> 73%) and simulated gastric juice (> 72%). Additionally, MKL8 demonstrated strong hydrophobicity (85%), auto-aggregation (87.3%-91.7%), and adherence to Caco-2 cells. Moreover, it had an inhibitory effect against pathogens too. By performing the hemolytic and MTT assays, the non-toxicity of MKL8 isolate was examined, and it exhibited no harmful characteristics. Considering MKL8's resistance to gastrointestinal tract conditions, high surface hydrophobicity, non-toxicity, and ability to inhibit the tested pathogens, it can be concluded that MKL8 demonstrated promising probiotic properties and has potential for use in the food industry.


Asunto(s)
Adhesión Bacteriana , Lactococcus lactis , Murraya , Probióticos , Humanos , Células CACO-2 , Lactococcus lactis/aislamiento & purificación , Adhesión Bacteriana/efectos de los fármacos , Murraya/química , Interacciones Hidrofóbicas e Hidrofílicas , Antibacterianos/farmacología
9.
Langmuir ; 40(26): 13648-13656, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38952282

RESUMEN

Controlling the spontaneous directional transport of droplets plays an important role in the application of microchemical reactions and microdroplet detection. Although the relevant technologies have been widely studied, the existing spontaneous droplet transport strategies still face problems of complex structure, single function, and poor flexibility. Inspired by the spontaneous droplet transport strategy in nature, an asymmetric wettability surface with microcone channels (AWS-MC) is prepared on a flexible fabric by combining surface modification and femtosecond laser manufacturing technology. On this surface, the capillary force and Laplace pressure induced by the wettability gradient and the geometric structure gradient drive the droplet transport from the hydrophobic surface to the hydrophilic surface. Notably, droplets in adjacent hydrophilic regions do not exchange substances even if the gap in the hydrophilic region is only 1 mm, which provides an ideal platform for numerous detections by a single drop. The droplet transport strategy does not require external energy and can adapt to the manipulation of various droplet types. Application of this surface in the blood of organisms is demonstrated. This work provides an effective method for microdroplet-directed self-transport and microdroplet detection.


Asunto(s)
Humectabilidad , Interacciones Hidrofóbicas e Hidrofílicas , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos , Animales , Propiedades de Superficie
10.
Sci Rep ; 14(1): 14832, 2024 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-38937649

RESUMEN

The structures of the Fc base of various IgG antibodies have been examined with a view to understanding how this region can be used to conjugate IgG to nanoparticles. The base structure is found to be largely consistent across a range of species and subtypes, comprising a hydrophobic region surrounded by hydrophilic residues, some of which are charged at physiological conditions. In addition, atomistic Molecular Dynamics simulations were performed to explore how model nanoparticles interact with the base using neutral and negatively charged gold nanoparticles. Both types of nanoparticle interacted readily with the base, leading to an adaptation of the antibody base surface to enhance the interactions. Furthermore, these interactions left the rest of the domain at the base of the Fc region structurally intact. This implies that coupling nanoparticles to the base of an IgG molecule is both feasible and desirable, since it leaves the antibody free to interact with its surroundings so that antigen-binding functionality can be retained. These results will therefore help guide future attempts to develop new nanotechnologies that exploit the unique properties of both antibodies and nanoparticles.


Asunto(s)
Oro , Fragmentos Fc de Inmunoglobulinas , Inmunoglobulina G , Nanopartículas del Metal , Simulación de Dinámica Molecular , Inmunoglobulina G/química , Inmunoglobulina G/inmunología , Fragmentos Fc de Inmunoglobulinas/química , Oro/química , Nanopartículas del Metal/química , Humanos , Nanopartículas/química , Interacciones Hidrofóbicas e Hidrofílicas , Animales
11.
Mol Pharm ; 21(7): 3540-3552, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38900044

RESUMEN

Molecular dynamics (MD) simulations of linear amylose fragments containing 10 to 40 glucose units were used to study the complexation of the prototypical compound, 3-pentadecylphenol (PDP)─a natural product with surfactant-like properties─in aqueous solution. The amylose-PDP binding leverages mainly hydrophobic interactions together with excluded volume effects. It was found that while the most stable complexes contained PDP inside the helical structure of the amylose in the expected guest-host (inclusion) complexation manner, at higher temperatures, the commonly observed PDP-amylose complexes often involved more nonspecific interactions than inclusion complexation. In the case where a stoichiometric excess of PDP was added to the simulation box, self-aggregation of the small molecule precluded its ability to enter the internal helical part of the oligosaccharide, and as a result, inclusion complexation became ineffective. MD simulation trajectories were analyzed preliminarily using cluster analysis (CA), followed by more rigorous solvent accessible surface area (SASA) determination over the temperature range spanning from 277 to 433 K. It was found that using the SASA of PDP corrected for its intrinsic conformational changes, together with a generic hidden Markov model (HMM), an adequate quantification of the different types of PDP-amylose aggregates was obtained to allow further analysis. The enthalpy change associated with the guest-host binding equilibrium constant (Kgh) in aqueous solution was estimated to be -75 kJ/mol, which is about twice as high as one might expect based on experimentally measured values of similar complexes in the solid state where the (unsolvated) helical structure of amylose remains rigid. On the other hand, the nonspecific binding (Kns) enthalpy change associated with PDP-amylose interactions in the same solution environment was found to be about half of the inclusion complexation value.


Asunto(s)
Amilosa , Simulación de Dinámica Molecular , Fenoles , Amilosa/química , Fenoles/química , Agua/química , Interacciones Hidrofóbicas e Hidrofílicas , Tensoactivos/química , Temperatura , Termodinámica
12.
Food Res Int ; 190: 114562, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38945563

RESUMEN

The structural and functional properties of whey-quercetin and whey hydrolysate-quercetin conjugates synthesized using alkaline and free radical-mediated methods (AM and FRM) coupled with sonication were studied. FTIR showed new peaks at 3000-3500 cm-1 (N-H stretching regions) and the 1000-1100 cm-1 region with the conjugates. Conjugation increased the random coils and α-helix content while decreasing the ß-sheets and turns. It also increased the particle size and surface hydrophobicity which was significantly (p < 0.05) higher in AM than FRM conjugates. AM conjugates had higher radical scavenging activity but lower quercetin content than FRM conjugates. Overall, the functional properties of whey-quercetin conjugates were better than whey hydrolysate-quercetin conjugates. However, hydrolysate conjugates had significantly higher denaturation temperatures irrespective of the method of production. Sonication improved the radical scavenging activity and quercetin content of FRM conjugates while it decreased both for AM conjugates. This study suggested that whey-quercetin conjugates generally had better quality than whey hydrolysate conjugates and sonication tended to further improve these properties. This study highlights the potential for using camel whey or whey hydrolysate-quercetin conjugates to enhance the functional properties of food products in the food industry.


Asunto(s)
Camelus , Interacciones Hidrofóbicas e Hidrofílicas , Quercetina , Sonicación , Quercetina/química , Animales , Hidrolisados de Proteína/química , Suero Lácteo/química , Antioxidantes/química , Proteína de Suero de Leche/química , Depuradores de Radicales Libres/química , Espectroscopía Infrarroja por Transformada de Fourier , Radicales Libres/química , Tamaño de la Partícula , Concentración de Iones de Hidrógeno
13.
Food Res Int ; 190: 114608, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38945618

RESUMEN

In dairy products, the added sodium hyaluronate may form complexes with proteins, thereby affecting product properties. In the present study, the interaction between whey protein isolate (WPI)/ whey protein hydrolysate (WPH) and sodium hyaluronate (SH) was characterized under thermal treatment at different temperatures (25 ℃, 65 ℃, 90 ℃ and 121 ℃) after studying effects of protein/SH ratio and pH on complex formation. The addition of SH reduced the particle size of WPI/WPH and increased potential value in the system, with greater variation with increasing treatment temperature. The structural properties of complexes were studied. The binding with SH decreased the contents of free amino group and free thiol group, as well as the fluorescence intensity and surface hydrophobicity. FTIR results and browning intensity measurement demonstrated the formation of Maillard reaction products. Moreover, the attachment of SH improved the thermal stability of WPI/WPH and decreased their antigenicity.


Asunto(s)
Calor , Ácido Hialurónico , Hidrolisados de Proteína , Proteína de Suero de Leche , Proteína de Suero de Leche/química , Ácido Hialurónico/química , Hidrolisados de Proteína/química , Concentración de Iones de Hidrógeno , Reacción de Maillard , Interacciones Hidrofóbicas e Hidrofílicas , Tamaño de la Partícula , Espectroscopía Infrarroja por Transformada de Fourier , Manipulación de Alimentos/métodos
14.
Food Res Int ; 190: 114659, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38945631

RESUMEN

Multi-layered structure of reconstituted meat-based products from minced fish was formed by physical extrusion, followed by an investigation into the impact of extrusion strength on structural and physicochemical properties before and after frying. Under an appropriate pressure (3-9 kPa), the air within minced fish underwent enrichment and rearrangement to form a stratified phase, promoting the formation of multi-layered structure during frying. Conversely, the lower pressure (≤1.5 kPa) was insufficient for phase separation and directional rearrangement, while the higher pressure (≥15 kPa) would cause the stratified phase to flow out of food system. Moreover, by directly increasing water mobility and meat compactness, physical extrusion indirectly caused more water loss and stronger ionic bonds during frying, which was positively correlated with multi-layered structure. However, an excessive pressure caused an increase in random coil and hydrophobic interactions during frying, which was negatively correlated with multi-layered structure. In conclusion, appropriate physical extrusion strength promoted the formation of multi-layered structure.


Asunto(s)
Culinaria , Productos de la Carne , Presión , Culinaria/métodos , Productos de la Carne/análisis , Animales , Manipulación de Alimentos/métodos , Productos Pesqueros/análisis , Calor , Interacciones Hidrofóbicas e Hidrofílicas , Agua/química , Peces , Fenómenos Químicos
15.
Yakugaku Zasshi ; 144(7): 715-732, 2024.
Artículo en Japonés | MEDLINE | ID: mdl-38945846

RESUMEN

An aqueous solution of 2,3-cis gallate type catechin (-)-epigallocatechin-3-O-gallate (EGCg) and caffeine afforded a precipitate of Creaming-down Phenomenon, which crystallized slowly for about three months to give a colorless block crystal. By X-ray crystallographic analysis, the crystal was determined to be a 2 : 2 complex of EGCg and caffeine, in which caffeine molecules were captured in a hydrophobic space formed with three aromatic A, B, and B' rings of EGCg. It was considered that the solubility of the 2 : 2 complex in water rapidly decreased and the 2 : 2 complex precipitated from aqueous solution. The hydrophobic spaces of EGCg captured a variety of heterocyclic compounds, and the molecular capture abilities of heterocyclic compounds using EGCg from the aqueous solutions were evaluated. Since the C ring of EGCg has two chiral carbon atoms, C2 and C3, the hydrophobic space of EGCg was a chiral space. EGCg captured diketopiperazine cyclo(Pro-Xxx) (Xxx=Phe, Tyr) and pharmaceuticals with a xanthine skeleton, proxyphylline and diprophylline, in the hydrophobic space, and recognized their chirality.


Asunto(s)
Cafeína , Catequina , Interacciones Hidrofóbicas e Hidrofílicas , Solubilidad , , Catequina/química , Catequina/análogos & derivados , Té/química , Cafeína/química , Cristalografía por Rayos X , Estereoisomerismo , Agua/química , Cristalización , Soluciones , Compuestos Heterocíclicos/química , Xantinas/química
16.
J Phys Chem B ; 128(25): 6049-6058, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38840325

RESUMEN

Lasioglossin-III (LL-III) is a potent broad-spectrum antimicrobial peptide used in diverse antimicrobial applications. In this work, coarse-grained and all-atom molecular dynamics simulation strategies were used in tandem to interpret the molecular mechanisms involved in the interfacial dynamics of LL-III and its recombinant variants during interactions with diverse cell membrane systems. Our results indicate that the membrane charges act as the driving force for initiating the membrane-peptide interactions, while the hydrophobic or van der Waals forces help to reinforce the membrane-peptide bindings. The optimized charge-hydrophobicity ratio of the LL-III peptides helps ensure their high specificity toward bacterial membranes compared to mammalian membrane systems, which also helps explain our experimental observations. Overall, we hope that our work gives new insight into the antimicrobial action of LL-III peptides and that the adopted simulation strategy will help other scientists and engineers extract maximal information from complex molecular simulations using minimal computational power.


Asunto(s)
Péptidos Catiónicos Antimicrobianos , Simulación de Dinámica Molecular , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Membrana Celular/química , Membrana Celular/metabolismo , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo
17.
Int J Mol Sci ; 25(12)2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38928076

RESUMEN

A high alkaline pH was previously demonstrated to enhance the extraction yield of brewer's spent grains (BSG) proteins. The effects of extraction pH beyond the extraction yield, however, has not been investigated before. The present work examined the effects of extraction pH (pH 8-12) on BSG proteins' (1) amino acid compositions, (2) secondary structures, (3) thermal stability, and (4) functionalities (i.e., water/oil holding capacity, emulsifying, and foaming properties). The ideal extraction temperature (60 °C) and BSG-to-solvent ratio (1:20 w/v) for maximizing the extraction yield were first determined to set the conditions for the pH effect study. The results showed that a higher extraction pH led to more balanced compositions between hydrophilic and hydrophobic amino acids and higher proportions of random coils structures indicating increased protein unfolding. This led to superior emulsifying properties of the extracted proteins with more than twofold improvement between pH 8 and a pH larger than 10. The extraction pH, nevertheless, had minimal impact on the water/oil holding capacity, foaming properties, and thermal denaturation propensity of the proteins. The present work demonstrated that a high alkaline pH at pH 11-12 was indeed ideal for both maximizing the extraction yield (37-46 wt.%) and proteins' functionalities.


Asunto(s)
Aminoácidos , Estabilidad Proteica , Estructura Secundaria de Proteína , Concentración de Iones de Hidrógeno , Aminoácidos/química , Aminoácidos/análisis , Interacciones Hidrofóbicas e Hidrofílicas , Proteínas de Granos/química , Temperatura , Grano Comestible/química
18.
Ultrason Sonochem ; 107: 106935, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38850642

RESUMEN

Myofibrillar proteins (MPs) have a notable impact on the firmness and flexibility of gel-based products. Therefore, enhancing the gelation and emulsification properties of scallop MPs is of paramount significance for producing high-quality scallop surimi products. In this study, we investigated the effects of high-intensity ultrasound on the physicochemical and gelation properties of MPs from bay scallops (Argopecten irradians). The carbonyl content of MPs significantly increased with an increase in ultrasound power (150, 350, and 550 W), indicating ultrasound-induced MP oxidation. Meanwhile, high-intensity ultrasound treatment (550 W) enhanced the emulsifying capacity and the short-term stability of MPs (up to 72.05 m2/g and 153.05 min, respectively). As the ultrasound power increased, the disulfide bond content and surface hydrophobicity of MPs exhibited a notable increase, indicating conformational changes in MPs. Moreover, in the secondary structure of MPs, the α-helix content significantly decreased, whereas the ß-sheet content increased, thereby suggesting the ultrasound-induced stretching and flexibility of MP molecules. Sodium-dodecyl sulfate-polyacrylamide gel electrophoresis and scanning electron microscopy analysis further elucidated that high-intensity ultrasound induced MP oxidation, leading to modification of amino acid side chains, intra- and intermolecular cross-linking, and MP aggregation. Consequently, high-intensity ultrasound treatment was found to augment the viscoelasticity, gel strength, and water-holding capacity of MP gels, because ultrasound treatment facilitated the formation of a stable network structure in protein gels. Thus, this study offers theoretical insights into the functional modification of bay scallop MPs and the processing of its surimi products.


Asunto(s)
Geles , Proteínas Musculares , Pectinidae , Pectinidae/química , Animales , Geles/química , Proteínas Musculares/química , Ondas Ultrasónicas , Fenómenos Químicos , Interacciones Hidrofóbicas e Hidrofílicas , Emulsiones/química
19.
J Biotechnol ; 391: 106-116, 2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-38871028

RESUMEN

Icaritin, a hydrolysate from total flavonoids of Epimedii (TFE), which has better anti-hepatoma activity than its glycosylated form. In this work, immobilized enzymes 4LP-Tpebgl3@Na-Y and DtRha@ES-107 were used to hydrolyze TFE to prepare icaritin. Five different hydrophobic deep eutectic solvents (HDES) were prepared and the most ideal HDES was successfully selected, which was composed of dodecyl alcohol and thymol with the molar ratio of 2:1. The relative enzyme activity of 4LP-Tpebgl3@Na-Y and DtRha@ES-107 was about 102.4 % and 112.5 %, respectively. In addition, the thermal and binding stability of 4LP-Tpebgl3@Na-Y and DtRha@ES-107 in HDES was not affected negatively. In the biphasic system composed of 50 % (v/v) HDES and Na2HPO4-citric acid buffer (50 mM, pH 5.5), 4LP-Tpebgl3@Na-Y (1.0 U/mL) and TFE (1 g/L) were reacted at 80 °C for 1 h, and then reacted with DtRha@ES-107 (20 U/mL) at 80 °C for 2 h. Finally, TFE was completely converted to 301.8 mg/L icaritin (0.82 mM). After 10 cycles, 4LP-Tpebgl3@Na-Y/DtRha@ES-107 still maintained 84.1 % original activity. In this study, we developed an efficient methodology for icaritin preparation through the integration of enzymatic catalysis and adsorption separation, presenting a viable approach for large-scale, cost-effective production of icaritin.


Asunto(s)
Biotransformación , Enzimas Inmovilizadas , Flavonoides , Interacciones Hidrofóbicas e Hidrofílicas , Flavonoides/metabolismo , Flavonoides/química , Enzimas Inmovilizadas/metabolismo , Enzimas Inmovilizadas/química , Disolventes Eutécticos Profundos/química , Disolventes Eutécticos Profundos/metabolismo , Epimedium/química , Epimedium/metabolismo , Hidrólisis , Solventes/química
20.
Biosensors (Basel) ; 14(6)2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38920592

RESUMEN

The scope of this study was to apply advances in materials science, specifically the use of organosilicate nanoparticles as a high surface area platform for passive sampling of chemicals or pre-concentration for active sensing in multiple-phase complex environmental media. We have developed a novel nanoporous organosilicate (NPO) film as an extraction phase and proof of concept for application in adsorbing hydrophobic compounds in water and sediment. We characterized the NPO film properties and provided optimization for synthesis and coatings in order to apply the technology in environmental media. NPO films in this study had a very high surface area, up to 1325 m2/g due to the high level of mesoporosity in the film. The potential application of the NPO film as a sorbent phase for sensors or passive samplers was evaluated using a model hydrophobic chemical, polychlorinated biphenyls (PCB), in water and sediment. Sorption of PCB to this porous high surface area nanoparticle platform was highly correlated with the bioavailable fraction of PCB measured using whole sediment chemistry, porewater chemistry determined by solid-phase microextraction fiber methods, and the Lumbriculus variegatus bioaccumulation bioassay. The surface-modified NPO films in this study were found to highly sorb chemicals with a log octanol-water partition coefficient (Kow) greater than four; however, surface modification of these particles would be required for application to other chemicals.


Asunto(s)
Sedimentos Geológicos , Interacciones Hidrofóbicas e Hidrofílicas , Nanopartículas , Nanopartículas/química , Agua/química , Bifenilos Policlorados/análisis , Contaminantes Químicos del Agua/análisis , Compuestos de Organosilicio/química , Adsorción , Propiedades de Superficie
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