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1.
J Colloid Interface Sci ; 607(Pt 1): 488-501, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34509120

RESUMO

HYPOTHESIS: Naturally derived or synthetic anticancer peptides (ACPs) have emerged as a new generation of anticancer agents with higher selectivity for cancer cells and less propensity for drug resistance. Despite the structural diversity of ACPs, α-helix is the most common secondary structure among them. Herein we report the development of a new library of short cationic amphiphilic α-helical ACPs with selective cytotoxicity against colorectal and cervical cancer. EXPERIMENTS: The peptides had a general formula C(XXYY)3 with C representing amino acid cysteine (providing a -SH group for molecular conjugation), X representing hydrophobic amino acids (isoleucine (I) or leucine (L)), and Y representing cationic amino acids (arginine (R) or lysine (K)). Two variants of the peptides were synthesized by adding additional Isoleucine residues to the C-terminal and replacing the N-terminal cysteine with LC-propargylglycine (LC-G) to investigate the effect of N-terminal and C-terminal variation on the anticancer activity. The structure and physicochemical properties of the peptides were determined by RP-HPLC, LC-MS and CD spectroscopy. The cytotoxicity of the peptides in different cell lines was assessed by MTT test, cell proliferation assay and mitochondrial damage assay. The mechanism of cell selectivity of the peptides was investigated by studying their interfacial behaviour at the air/water and lipid/water interface using Langmuir trough. FINDINGS: The peptides consisting of K residues in their hydrophilic domains exhibited more selective anticancer activity whereas the peptides containing R exhibited strong toxicity in normal cells. The anticancer activity of the peptides was a function of their helical content and their hydrophobicity. Therefore, the addition of two I residues at C-terminal enhanced the anticancer activity of the peptides by increasing their hydrophobicity and their helical content. These two variants also exhibited strong anticancer activity against colorectal cancer multicellular tumour spheroids (MCTS). The higher toxicity of the peptides in cancer cells compared to normal cells was the result of higher penetration into the negatively charged cancer cell membranes, leading to higher cellular uptake, and their cytotoxic effect was mainly exerted by damaging the mitochondrial membranes leading to apoptosis. The results from this study provide a basis for rational design of new α-helical ACPs with enhanced anticancer activity and selectivity.


Assuntos
Peptídeos , Cátions , Dicroísmo Circular , Interações Hidrofóbicas e Hidrofílicas , Peptídeos/farmacologia , Conformação Proteica em alfa-Hélice , Estrutura Secundária de Proteína
2.
Food Chem ; 370: 131070, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34537424

RESUMO

Bioactive peptides derived from food proteins have various physiological roles and have attracted increasing attention in recent years. In this study, two novel ACE inhibitory peptides (EACF and CDF), screened from rabbit meat proteins using in silico methods, exhibited strong inhibitory effects in vitro. EACF and CDF were competitive and non-competitive inhibitors with half-maximal inhibitory concentrations of 41.06 ± 0.82 µM and 192.17 ± 2.46 µM, respectively. Molecular docking experiments revealed that EACF established eight H-bond interactions in the S1 and S2 pockets, and a metal-acceptor interaction with Zn 701. CDF shared four H-bond interactions in the S1 pocket of ACE. The results suggested that rabbit meat proteins could be a suitable material for the preparation of ACE inhibitory peptides, and that virtual screening is an effective, accurate and promising method for the discovery of novel active peptides.


Assuntos
Inibidores da Enzima Conversora de Angiotensina , Peptidil Dipeptidase A , Angiotensinas , Animais , Simulação por Computador , Proteínas de Carne , Simulação de Acoplamento Molecular , Peptídeos , Coelhos
3.
Food Chem ; 371: 131105, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34537606

RESUMO

Umami peptides have become of key interest in the development of flavoring agents. However, the lack of known umami peptides further prevents the understanding of the umami mechanism. The famous pufferfish (Takifugu flavidus) is a great resource for novel umami peptides, and we further analyze the umami characteristics of peptides based on multi-evaluation. In this study, five novel umami peptides, DF9, TK18, AK11, IK10, and GT12 were found; DF9 having the highest umami intensity, followed by AK11. Moreover, biosensor results showed DF9 with the lowest Ka value of 6.85 × 10-13 mol/L, followed by AK11. These data are mostly in agreement with sensory evaluation and fully reveal the umami mechanism of peptides. Quantum chemical and molecular docking demonstrated active site D in peptides bound with T1R1 receptor. Our results open up new strategies to estimate the taste characteristics of umami peptides and provide rational tools for screening umami peptides in food.


Assuntos
Peptídeos , Paladar , Animais , Aromatizantes , Simulação de Acoplamento Molecular , Receptores Acoplados a Proteínas G , Takifugu
4.
Food Chem ; 372: 131235, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34624781

RESUMO

In this study, a new surface-enhanced Raman scattering (SERS)-based method has been developed for the detection of plasmin activity. Firstly, different peptide sequences, which are specific to plasmin, were examined. Then, SERS substrates were prepared by chosen peptide substrate. Enzyme activity was determined by pursuing the reduction of DTNB band at 1331 cm-1 with Raman spectroscopy. The reduction in SERS intensity was related to the plasmin activity, and changes in SERS intensity vs. plasmin concentration graph was obtained. Limit of detection (LOD) and limit of quantification (LOQ) values were calculated as 2.14 U/mL and 6.42 U/mL, respectively. Intra- and inter-day repeatability results were determined as 1.45% and 1.47% relative standard deviation (RSD). Also, recovery of the method was determined for the plasmin spiked milk samples. The results demonstrated that the proposed method could be successfully used to detect the plasmin activity in milk samples.


Assuntos
Nanopartículas Metálicas , Análise Espectral Raman , Fibrinolisina , Ouro , Limite de Detecção , Peptídeos
5.
Food Chem ; 372: 131266, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34628117

RESUMO

The food-derived peptides hydrolyzed from native food protein matrix exhibited various bioactivities and multimeric structures, which make them the promising well-defined nanoplatforms candidates to co-deliver themselves with other bioactive compounds. In this study, zein-egg white derived peptides-chitosan (Z-EWDP-CS) ternary nanoparticles (NPs) were successfully fabricated by the spontaneous assembly to enhance the stability and bioactivity of curcumin (Cur). The novel ternary NPs exhibited a typical nano-spherical structure (138.63 nm, 40.50 mV), and adorable encapsulation efficiency (EE, 93.87%) for Cur. FTIR, XRD and DSC results verified that Cur changed from a crystalline state to an amorphous state, and was successfully entrapped in the cavity of Z-EWDP-CS NPs. Furthermore, the thermal stability, photochemical stability, salt stability, and antioxidant activity were considerably improved in the NPs after the addition of EWDP. Our results demonstrate that the food-derived peptides could be an ideal affinity agent for the co-delivery of themselves with hydrophobic nutraceuticals.


Assuntos
Quitosana , Curcumina , Nanopartículas , Zeína , Clara de Ovo , Tamanho da Partícula , Peptídeos
6.
Methods Mol Biol ; 2414: 47-62, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34784031

RESUMO

The bacterial cell surface (surfaceome) is the first site encountered by immune cells and is thus an important site for immune recognition. As such, the characterization of bacterial surface proteins can lead to the discovery of novel antigens for potential vaccine development. In this chapter, we describe a rapid 5-min surface shaving proteomics protocol where live bacterial cells are incubated with trypsin and surface peptides are "shaved" off. The shaved peptides are subsequently identified with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Several checkpoints, including colony forming unit (CFU) counts, flow cytometry, and a false positive unshaved control, are introduced to ensure cell viability/membrane integrity are maintained and that proteins identified are true surface proteins. The protein topology of shaved peptides can be bioinformatically confirmed for surface location. Surface shaving facilitates identification of surface proteins expressed under different conditions, by different strains as well as highly abundant essential and immunogenic bacterial surface antigens for potential vaccine development.


Assuntos
Proteômica , Vacinas , Antígenos de Bactérias , Antígenos de Superfície , Bactérias , Proteínas de Bactérias , Cromatografia Líquida , Proteínas de Membrana , Peptídeos , Espectrometria de Massas em Tandem
7.
Methods Mol Biol ; 2414: 141-149, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34784036

RESUMO

A variety of delivery vehicles have been explored as adjuvanting/delivery platforms for peptide-based subunit vaccines. Polysaccharide-based systems have been found to be especially attractive due to their immune stimulating properties, biodegradability, biocompatibility, and low toxicity. Among them, chitosan and its derivatives are the most common cationic nanocarriers used for the delivery of antigens. Trimethyl chitosan (TMC) is a partially quaternized, water-soluble, and mucoadhesive derivative of chitosan. This chapter describes the preparation of a TMC-based polyelectrolyte complex as a delivery system for peptide subunit vaccines.


Assuntos
Polieletrólitos , Quitosana , Portadores de Fármacos , Nanopartículas , Peptídeos , Vacinas de Subunidades
8.
Food Chem ; 371: 131124, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34563972

RESUMO

Takifugu obscurus (T. obscurus) is known for its umami taste. Two taste-active peptides, Pro-Val-Ala-Arg-Met-Cys-Arg (PR-7) and Tyr-Gly-Gly-Thr-Pro-Pro-Phe-Val (YV-8), were proved as key compounds that contributed to the typical taste of T. obscurus. However, whether these peptides have the potential as umami supplements is unknown. The purpose of this study was to investigate the taste characteristics of PR-7 and YV-8, as well as stability at different pH values by sensory evaluation, instrumental analysis and quantum chemical calculation. The results indicated that PR-7 and YV-8 presented umami taste at near neutral pH (6.5-8.0) and had umami-enhancing effects. PR-7 also exhibited significant kokumi activity. Additionally, two peptides showed remarkable stability after different pH treatments, especially YV-8; this may be related to its stable structural property. All the results suggest that both peptides have great potential to be applied in complex foods to provide desirable taste, and act as a feasible alternative to monosodium l-glutamate.


Assuntos
Takifugu , Paladar , Animais , Peptídeos , Glutamato de Sódio
9.
Food Chem ; 372: 131322, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34818740

RESUMO

In this work, based on a specific antibody was obtained from the Protein Data Bank (PDB), a library of the specific peptides of aflatoxin B1 (AFB1) was constructed by combining key amino acids, amino acid mutations and molecular docking. Then, the porous gold nanoparticles (porous AuNPs) were fabricated on the surface of a glassy carbon electrode (GCE). A novel, sensitive and no-label signal immunosensor was developed by signal enhancement with the specific peptide as the recognition element for the detection of AFB1 in cereals. Under the optimal conditions, the limit of detection (S/N = 3) was 9.4 × 10-4 µg·L-1, and the linear range was 0.01 µg·L-1 to 20 µg·L-1. The recovery results were 88.4%∼102.0%, which indicated an excellent accuracy. This sensor is an ideal candidate for screening the peptides of AFB1, and a novel immunosensor was used to detect AFB1 in cereals.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Aflatoxina B1/análise , Técnicas Eletroquímicas , Ouro , Imunoensaio , Limite de Detecção , Simulação de Acoplamento Molecular , Peptídeos
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 265: 120378, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34543989

RESUMO

The structure of water, especially around the solute is thought to play an important role in many biological and chemical processes. Water-peptide and cosolvent-peptide interactions are crucial in determining the structure and function of protein molecules. In this work, we present the H-bonding analysis for model peptides like glycyl-glycine (gly-gly), glycine-ւ-valine (gly-val), glycyl-ւ-leucine (gly-leu) and triglycine (trigly) and triethylammonium based carboxylate protic ionic liquids (PILs) in aqueous solutions as well as for peptides in ∼0.2 mol·L-1 of aqueous PIL solutions in the spectral range of 7800-5500 cm-1 using Fourier transform near-infrared (FT-NIR) spectroscopy at 298.15 K. The hydration numbers for peptides and PILs were obtained using NIR method of simultaneous estimation of hydration spectrum and hydration number of a solute dissolved in water. The H-bond of water molecules around peptides and PILs are found to be stronger and shorter than those in pure liquid water. We observe that the hydration shell around zwitterions is a clathrate-like cluster of water in which ions entrap. Watery network analysis confirms that singly H-bonded species or NHBs changes to partial or distorted ice-like structures of water in the hydration shell of PILs. The overall water H-bonding in the hydration sphere of PILs increases in the order TEAF < TEAA < TEAG < TEAPy ≈ TEAP < TEAB. The influence of PILs on hydration behavior of peptides is explored in terms of H-bonding, cooperativity, hydrophobicity, water structural changes, ionic interactions etc.


Assuntos
Líquidos Iônicos , Glicina , Peptídeos , Soluções , Água
11.
J Colloid Interface Sci ; 606(Pt 2): 1974-1982, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34749446

RESUMO

The use of isotropic potential models of simple colloids for describing complex protein-protein interactions is a topic of ongoing debate in the biophysical community. This contention stems from the unavailability of synthetic protein-like model particles that are amenable to systematic experimental characterization. In this article, we test the utility of colloidal theory to capture the solution structure, interactions and dynamics of novel globular protein-mimicking, computationally designed peptide assemblies called bundlemers that are programmable model systems at the intersection of colloids and proteins. Small-angle neutron scattering (SANS) measurements of semi-dilute bundlemer solutions in low and high ionic strength solution indicate that bundlemers interact locally via repulsive interactions that can be described by a screened repulsive potential. We also present neutron spin echo (NSE) spectroscopy results that show high-Q freely-diffusive dynamics of bundlemers. Importantly, formation of clusters due to short-range attractive, inter-bundlemer interactions is observed in SANS even at dilute bundlemer concentrations, which is indicative of the complexity of the bundlemer charged surface. The similarities and differences between bundlemers and simple colloidal as well as complex protein-protein interactions is discussed in detail.


Assuntos
Coloides , Peptídeos , Difusão , Proteínas , Espalhamento a Baixo Ângulo
12.
J Colloid Interface Sci ; 606(Pt 2): 2038-2050, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34749450

RESUMO

We report on charge transport across self-assembled monolayers (SAMs) of short tau peptides by probing the electron tunneling rates and quantum mechanical simulation. We measured the electron tunneling rates across SAMs of carboxyl-terminated linker molecules (C6H12O2S) and short cis-tau (CT) and trans-tau (TT) peptides, supported on template-stripped gold (AuTS) bottom electrode, with Eutectic Gallium-Indium (EGaIn)(EGaIn) top electrode. Measurements of the current density across thousands of AuTS/linker/tau//Ga2O3/EGaIn single-molecule junctions show that the tunneling current across CT peptide is one order of magnitude lower than that of TT peptide. Quantum mechanical simulation demonstrated a wider energy bandgap of the CT peptide, as compared to the TT peptide, which causes a reduction in its electron tunneling current. Our findings also revealed the critical role of phosphorylation in altering the charge transport characteristics of short peptides; more specifically, we found that the presence of phosphate groups can reduce the energy band gap in tau peptides and alter their electrical properties. Our results suggest that conformational and phosphorylation of short peptides (e.g., tau) can significantly change their charge transport characteristics and energy levels.


Assuntos
Elétrons , Gálio , Índio , Peptídeos , Fosforilação
13.
J Pharm Biomed Anal ; 207: 114426, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34689062

RESUMO

Alcoholism is a severe threat to public health, and there are no adequate treatments for alcoholic liver disease. The aim of this study was to identify bioactive peptides derived from natural proteins that prevent acute alcohol-induced liver injury. We identified a peptide with the sequence Gly-Leu-hydroxyproline-Gly-Glu-Arg (GLpGER) from the hydrolysate of crucian carp swim bladder using size-exclusion chromatography and reversed-phase chromatography. The in vitro EC50 value of GLpGER to activate alcohol dehydrogenase (ADH) was 137.9 ± 9 µM. Molecular docking experiments indicated that the mechanism by which GLpGER activates ADH may be related to the formation of stable complexes with ADH active pockets through hydrogen bonding, and electrostatic and hydrophobic interactions. Oral administration of GLpGER one hour before acute alcohol ingestion significantly increased alcohol metabolism, manifesting as reduced incidence of the loss of righting reflex, increased alcohol tolerance time, shortened sobering time, and decreased blood alcohol concentration level. GLpGER restored liver ADH activity, maintained the typical morphology of hepatocytes, and reduced serum levels of alanine aminotransferase and aspartate aminotransferase. These findings suggest that GLpGER might reduce acute alcohol-induced liver injury and may have the potential to be developed as an anti-inebriation ingredient.


Assuntos
Carpas , Doença Hepática Crônica Induzida por Substâncias e Drogas , Álcool Desidrogenase , Animais , Concentração Alcoólica no Sangue , Etanol , Fígado , Camundongos , Simulação de Acoplamento Molecular , Peptídeos , Bexiga Urinária
14.
J Colloid Interface Sci ; 605: 410-424, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34332414

RESUMO

In the inflammatory peri-implant microenvironment, excessive polarization of macrophages to the proinflammatory M1 phenotype can trigger the secretion of inflammatory cytokines, which promote bone resorption and impede osteogenesis around implants. The direct consequence of this process is the failure of prosthetic implants due to aseptic loosening. To reverse the inflammatory microenvironment and prevent prosthesis loosening, a mussel adhesion-inspired surface strategy was used for bioengineering of titanium implants with integrin-binding ability. In our design, a mussel-inspired catecholic peptide with tetravalent 3,4-dihydroxy-l-phenylalanine (DOPA) and Arg-Gly-Asp (RGD) sequences was synthesized. The peptide can easily anchor to the surface of medical titanium materials through a mussel adhesive mechanism. We found that peptide-decorated titanium implants could effectively inhibit peri-implant inflammation in a wear particle model and could promote the polarization of macrophages to a pro-healing M2 phenotype by interfering with integrin-α2ß1 and integrin-αvß3. Moreover, the peptide coating increased the adherence of osteoblasts and promoted osteogenesis on titanium implants even under inflammatory conditions. This work suggested that this biomimetic catecholic integrin-binding peptide can provide facile tactics for surface bioengineering of medical prostheses with improved interfacial osteogenesis under inflammatory conditions, which might contribute greatly to the prevention of prosthesis loosening and the improvement of clinical outcomes.


Assuntos
Osteogênese , Titânio , Humanos , Inflamação/etiologia , Peptídeos , Próteses e Implantes
15.
J Colloid Interface Sci ; 605: 493-499, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34371421

RESUMO

The interaction of proteins and peptides with inorganic surfaces is relevant in a wide array of technological applications. A rational approach to design peptides for specific surfaces would build on amino-acid and surface specific interaction models, which are difficult to characterize experimentally or by modeling. Even with such a model at hand, the large number of possible sequences and the large conformation space of peptides make comparative simulations challenging. Here we present a computational protocol, the effective implicit surface model (EISM), for efficient in silico evaluation of the binding affinity trends of peptides on parameterized surface, with a specific application to the widely studied gold surface. In EISM the peptide surface interactions are modeled with an amino-acid and surface specific implicit solvent model, which permits rapid exploration of the peptide conformational degrees of freedom. We demonstrate the parametrization of the model and compare the results with all-atom simulations and experimental results for specific peptides.


Assuntos
Ouro , Peptídeos , Adsorção , Proteínas , Solventes , Propriedades de Superfície
16.
Food Chem ; 368: 130839, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34419799

RESUMO

Human bitter taste receptor TAS2R14 (T2R14) can widely perceive bitterness, which has always been an issue for people to overcome. This study was aimed at identifying bioactive peptides obtained from Oncorhynchus mykiss nebulin hydrolysates as bitter taste receptor blockers by physicochemical property prediction, molecular docking, and in vitro determination of bitterness intensity using electronic tongue. Exploration of the interaction mechanism of these peptides with T2R14 by molecular docking models indicated that peptides ADM and ADW had high affinities for T2R14 to block the binding of bitter substances into the receptor. Addition of ADM and ADW to quinine caused reduction in bitterness intensity, with IC50 values of 420.32 ± 6.26 µM and 403.29 ± 4.10 µM, respectively. Hydrogen bond interaction and hydrophobic interaction were responsible for manifesting the high affinities of these peptides for the receptor. Residues Thr86, Asp168, and Phe247 may be the key amino acids within the binding site.


Assuntos
Proteínas de Peixes/genética , Proteínas Musculares/genética , Oncorhynchus mykiss , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Paladar , Animais , Humanos , Simulação de Acoplamento Molecular , Oncorhynchus mykiss/genética , Peptídeos/genética , Receptores Acoplados a Proteínas G/genética
17.
Talanta ; 236: 122886, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635266

RESUMO

Rheumatoid arthritis (RA), an autoimmune and chronic inflammatory disorder, is an incurable disease. We developed a peptide-based electrochemical sensor using electrochemical impedance spectroscopy that can be used to detect autoantibodies for RA diagnostics. We first validated that the developed peptide showed high sensitivity and could compliment the current gold standard method of an anti-cyclic citrullinated peptide antibody (anti-CCP) ELISA. The developed peptide can be modified on the nanogold surface of the working electrode of sensing chips through the method of a self-assembling monolayer. The sensing process was first optimized using a positive control cohort and a healthy control cohort. Subsequently, 10 clinically confirmed samples from RA patients and five healthy control samples were used to find the threshold value of the impedance between RA and healthy subjects. Furthermore, 10 clinically confirmed samples but with low values of anti-CCP autoantibodies were used to evaluate the sensitivity of the present method compared to the conventional method. The proposed method showed better sensitivity than the current conventional anti-CCP ELISA method.


Assuntos
Artrite Reumatoide , Artrite Reumatoide/diagnóstico , Espectroscopia Dielétrica , Impedância Elétrica , Ensaio de Imunoadsorção Enzimática , Humanos , Peptídeos
18.
Food Chem ; 366: 130494, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34293544

RESUMO

Bioactive peptides have recently gained more research attention as potential therapies for the management of bodily disorders and metabolic syndromes of delicate health importance. On another note, there is a rising trend on a global scale for the consumption and adoption of fruit and vegetables for the fulfilment of dietary and health needs. Furthermore, fruits and vegetables are being more studied as base materials for the isolation of biologically functional components and accordingly, they have been investigated for their concomitant bioactive peptides. This review focuses on isolation and bio-functional properties of bioactive peptides from fruits and vegetables. This manuscript is potential in serving as a material collection for fundamental consultancy on peptides derived from fruits and vegetables, and further canvasses the necessitation for the use of these food materials as primal matter for such.


Assuntos
Frutas , Verduras , Dieta , Peptídeos
19.
Food Chem ; 366: 130626, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34325244

RESUMO

The protective effects of the peptides Asp-Asp-Asp-Tyr (DDDY) and Asp-Tyr-Asp-Asp (DYDD) against AAPH-induced HepG2 cells are unclear. Our objective was to investigate the active sites of these peptides and their cellular antioxidant mechanism. DDDY and DYDD show a direct free radical scavenging effect in reducing ROS levels and maintained cellular antioxidant enzymes at normal levels. The quantum chemistry analysis of the electronic properties of antioxidant activity showed that DYDD has a greater energy in the highest occupied molecular orbital than DDDY, and O58-H59 and N10-H12 were identified as the active antioxidant sites in DYDD and DDDY, respectively, indicating that the inconsistent arrangement of amino acids affects the distribution of the highest occupied orbital energy as well as the active sites; thus, influences the antioxidant activity of peptides. It provide valuable insights into the antioxidant active sites of peptides.


Assuntos
Estresse Oxidativo , Peptídeos , Antioxidantes/farmacologia , Domínio Catalítico , Dipeptídeos
20.
Food Chem ; 366: 130643, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34330031

RESUMO

To protect walnut peptides from harsh external environments during their storage and digestion, proliposomes loaded with walnut peptides were fabricated using sucrose, trehalose, and mannitol as carriers and lyoprotectants. The physicochemical properties, environmental stability, antioxidant/antibacterial activities, and digestion in vitro of the proliposomes were evaluated. The freshly prepared liposomes were uniform in size, but the hydrated proliposomes showed a more uneven size distribution. The lyoprotectants helped maintain favorable liposome shape during lyophilization. Alongside the lyoprotectants, the walnut peptides further stabilized the lipid bilayer. Proliposomes encapsulation didn't impact the peptides' antioxidant activity. Furthermore, walnut peptides-loaded proliposomes exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. The proliposomes were stable during gastric-phase digestion. The lyoprotectants changed the free fatty acid release behaviors of the proliposomes. These characteristics suggest potential applications for proliposomes as effective delivery systems for biopeptides in food stuffs, thereby protecting bioactivities during storage and passage through the gastrointestinal tract.


Assuntos
Antioxidantes , Juglans , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Lipossomos , Tamanho da Partícula , Peptídeos
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