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1.
Sci Rep ; 14(1): 11533, 2024 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773170

RESUMEN

Tauopathies, including Alzheimer's disease and Frontotemporal Dementia, are debilitating neurodegenerative disorders marked by cognitive decline. Despite extensive research, achieving effective treatments and significant symptom management remains challenging. Accurate diagnosis is crucial for developing effective therapeutic strategies, with hyperphosphorylated protein units and tau oligomers serving as reliable biomarkers for these conditions. This study introduces a novel approach using nanotechnology to enhance the diagnostic process for tauopathies. We developed humanized ferritin nanocages, a novel nanoscale delivery system, designed to encapsulate and transport a tau-specific fluorophore, BT1, into human retinal cells for detecting neurofibrillary tangles in retinal tissue, a key marker of tauopathies. The delivery of BT1 into living cells was successfully achieved through these nanocages, demonstrating efficient encapsulation and delivery into retinal cells derived from human induced pluripotent stem cells. Our experiments confirmed the colocalization of BT1 with pathological forms of tau in living retinal cells, highlighting the method's potential in identifying tauopathies. Using ferritin nanocages for BT1 delivery represents a significant contribution to nanobiotechnology, particularly in neurodegenerative disease diagnostics. This method offers a promising tool for the early detection of tau tangles in retinal tissue, with significant implications for improving the diagnosis and management of tauopathies. This study exemplifies the integration of nanotechnology with biomedical science, expanding the frontiers of nanomedicine and diagnostic techniques.


Asunto(s)
Ferritinas , Retina , Tauopatías , Proteínas tau , Humanos , Proteínas tau/metabolismo , Ferritinas/metabolismo , Retina/metabolismo , Retina/patología , Tauopatías/metabolismo , Tauopatías/patología , Tauopatías/diagnóstico , Células Madre Pluripotentes Inducidas/metabolismo , Ovillos Neurofibrilares/metabolismo , Ovillos Neurofibrilares/patología
2.
Pharmaceuticals (Basel) ; 17(3)2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38543184

RESUMEN

Lactoferrins and lactoferrin-derived peptides display numerous functions linked to innate immunity in mammalians, spanning from antimicrobial to anti-inflammatory and immunomodulatory actions, and even demonstrate antitumor properties. To date, the proposed mechanisms for their biological actions are varied, although the molecular basis that governs lactoferrin interactions with molecular targets has been clarified only in a limited number of specific cases. However, key in silico methods have recently moved the topic to the fore, thus greatly expanding the possibilities of large-scale investigations on macromolecular interactions involving lactoferrins and their molecular targets. This review aims to summarize the current knowledge on the structural determinants that drive lactoferrin recognition of molecular targets, with primary focus on the mechanisms of activity against bacteria and viruses. The understanding of the structural details of lactoferrins' interaction with their molecular partners is in fact a crucial goal for the development of novel pharmaceutical products.

3.
Pharmaceutics ; 16(3)2024 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-38543296

RESUMEN

Chronic lymphocytic leukemia (CLL) is a widespread type of leukemia that predominantly targets B lymphocytes, undermining the balance between cell proliferation and apoptosis. In healthy B cells, miR-15/16, a tandem of microRNAs, functions as a tumor suppressor, curbing the expression of the antiapoptotic B cell lymphoma 2 protein (Bcl-2). Conversely, in CLL patients, a recurring deletion on chromosome 13q14, home to the miR15-a and miR16-1 genes, results in Bcl-2 overexpression, thereby fostering the onset of the pathology. In the present research, a novel approach utilizing humanized ferritin-based nanoparticles was employed to successfully deliver miR15-a and miR-16-1 into MEG01 cells, a model characterized by the classic CLL deletion and overexpression of the human ferritin receptor (TfR1). The loaded miR15-a and miR16-1, housed within modified HumAfFt, were efficiently internalized via the MEG01 cells and properly directed into the cytoplasm. Impressively, the concurrent application of miR15-a and miR16-1 demonstrated a robust capacity to induce apoptosis through the reduction in Bcl-2 expression levels. This technology, employing RNA-loaded ferritin nanoparticles, hints at promising directions in the battle against CLL, bridging the substantial gap left by traditional transfection agents and indicating a pathway that may offer hope for more effective treatments.

4.
Protein Sci ; 32(12): e4819, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37883077

RESUMEN

Ferritin, a naturally occurring iron storage protein, has gained significant attention as a drug delivery platform due to its inherent biocompatibility and capacity to encapsulate therapeutic agents. In this study, we successfully genetically engineered human H ferritin by incorporating 4 or 6 tryptophan residues per subunit, strategically oriented towards the inner cavity of the nanoparticle. This modification aimed to enhance the encapsulation of hydrophobic drugs into the ferritin cage. Comprehensive characterization of the mutants revealed that only the variant carrying four tryptophan substitutions per subunit retained the ability to disassemble and reassemble properly. As a proof of concept, we evaluated the loading capacity of this mutant with ellipticine, a natural hydrophobic indole alkaloid with multimodal anticancer activity. Our data demonstrated that this specific mutant exhibited significantly higher efficiency in loading ellipticine compared to human H ferritin. Furthermore, to evaluate the versatility of this hydrophobicity-enhanced ferritin nanoparticle as a drug carrier, we conducted a comparative study by also encapsulating doxorubicin, a commonly used anticancer drug. Subsequently, we tested both ellipticine and doxorubicin-loaded nanoparticles on a promyelocytic leukemia cell line, demonstrating efficient uptake by these cells and resulting in the expected cytotoxic effect.


Asunto(s)
Antineoplásicos , Elipticinas , Nanopartículas , Humanos , Ferritinas/genética , Ferritinas/química , Apoferritinas/genética , Triptófano , Antineoplásicos/farmacología , Antineoplásicos/química , Sistemas de Liberación de Medicamentos , Portadores de Fármacos/química , Doxorrubicina/farmacología , Doxorrubicina/química , Nanopartículas/química , Interacciones Hidrofóbicas e Hidrofílicas , Línea Celular Tumoral
5.
Molecules ; 28(3)2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36770830

RESUMEN

Superparamagnetic iron oxide nanoparticles (SPIONs) may act as an excellent theragnostic tool if properly coated and stabilized in a biological environment, even more, if they have targeting properties towards a specific cellular target. Humanized Archaeoglobus fulgidus Ferritin (HumAfFt) is an engineered ferritin characterized by the peculiar salt-triggered assembly-disassembly of the hyperthermophile Archaeoglobus fulgidus ferritin and is successfully endowed with the human H homopolymer recognition sequence by the transferrin receptor (TfR1 or CD71), overexpressed in many cancer cells in response to the increased demand of iron. For this reason, HumAfFt was successfully used in this study as a coating material for 10 nm SPIONs, in order to produce a new magnetic nanocarrier able to discriminate cancer cells from normal cells and maintain the potential theragnostic properties of SPIONs. HumAfFt-SPIONs were exhaustively characterized in terms of size, morphology, composition, and cytotoxicity. The preferential uptake capacity of cancer cells toward HumAfFt-SPIONs was demonstrated in vitro on human breast adenocarcinoma (MCF7) versus normal human dermal fibroblast (NHDF) cell lines.


Asunto(s)
Nanopartículas de Magnetita , Neoplasias , Humanos , Ferritinas , Línea Celular , Nanopartículas Magnéticas de Óxido de Hierro , Fenómenos Magnéticos
6.
Front Mol Biosci ; 10: 1332359, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38250735

RESUMEN

The development of methods able to modulate the binding affinity between proteins and peptides is of paramount biotechnological interest in view of a vast range of applications that imply designed polypeptides capable to impair or favour Protein-Protein Interactions. Here, we applied a peptide design algorithm based on shape complementarity optimization and electrostatic compatibility and provided the first experimental in vitro proof of the efficacy of the design algorithm. Focusing on the interaction between the SARS-CoV-2 Spike Receptor-Binding Domain (RBD) and the human angiotensin-converting enzyme 2 (ACE2) receptor, we extracted a 23-residues long peptide that structurally mimics the major interacting portion of the ACE2 receptor and designed in silico five mutants of such a peptide with a modulated affinity. Remarkably, experimental KD measurements, conducted using biolayer interferometry, matched the in silico predictions. Moreover, we investigated the molecular determinants that govern the variation in binding affinity through molecular dynamics simulation, by identifying the mechanisms driving the different values of binding affinity at a single residue level. Finally, the peptide sequence with the highest affinity, in comparison with the wild type peptide, was expressed as a fusion protein with human H ferritin (HFt) 24-mer. Solution measurements performed on the latter constructs confirmed that peptides still exhibited the expected trend, thereby enhancing their efficacy in RBD binding. Altogether, these results indicate the high potentiality of this general method in developing potent high-affinity vectors for hindering/enhancing protein-protein associations.

7.
Int J Mol Sci ; 23(12)2022 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35742969

RESUMEN

Amine oxidases are enzymes belonging to the class of oxidoreductases that are widespread, from bacteria to humans. The amine oxidase from Lathyrus cicera has recently appeared in the landscape of biocatalysis, showing good potential in the green synthesis of aldehydes. This enzyme catalyzes the oxidative deamination of a wide range of primary amines into the corresponding aldehydes but its use as a biocatalyst is challenging due to the possible inactivation that might occur at high product concentrations. Here, we show that the enzyme's performance can be greatly improved by immobilization on solid supports. The best results are achieved using amino-functionalized magnetic microparticles: the immobilized enzyme retains its activity, greatly improves its thermostability (4 h at 75 °C), and can be recycled up to 8 times with a set of aromatic ethylamines. After the last reaction cycle, the overall conversion is about 90% for all tested substrates, with an aldehyde production ranging between 100 and 270 mg depending on the substrate used. As a proof concept, one of the aldehydes thus produced was successfully used for the biomimetic synthesis of a non-natural benzylisoquinoline alkaloid.


Asunto(s)
Lathyrus , Aldehídos , Aminas , Biocatálisis , Enzimas Inmovilizadas/metabolismo , Humanos , Lathyrus/metabolismo , Fenómenos Magnéticos , Monoaminooxidasa/metabolismo , Oxidorreductasas/metabolismo
8.
Int J Mol Sci ; 23(10)2022 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-35628247

RESUMEN

The present investigation focuses on the analysis of the interactions among human lactoferrin (LF), SARS-CoV-2 receptor-binding domain (RBD) and human angiotensin-converting enzyme 2 (ACE2) receptor in order to assess possible mutual interactions that could provide a molecular basis of the reported preventative effect of lactoferrin against CoV-2 infection. In particular, kinetic and thermodynamic parameters for the pairwise interactions among the three proteins were measured via two independent techniques, biolayer interferometry and latex nanoparticle-enhanced turbidimetry. The results obtained clearly indicate that LF is able to bind the ACE2 receptor ectodomain with significantly high affinity, whereas no binding to the RBD was observed up to the maximum "physiological" lactoferrin concentration range. Lactoferrin, above 1 µM concentration, thus appears to directly interfere with RBD-ACE2 binding, bringing about a measurable, up to 300-fold increase of the KD value relative to RBD-ACE2 complex formation.


Asunto(s)
Enzima Convertidora de Angiotensina 2 , COVID-19 , Lactoferrina , SARS-CoV-2 , Enzima Convertidora de Angiotensina 2/antagonistas & inhibidores , Enzima Convertidora de Angiotensina 2/metabolismo , COVID-19/metabolismo , COVID-19/virología , Humanos , Lactoferrina/metabolismo , Peptidil-Dipeptidasa A/metabolismo , Dominios y Motivos de Interacción de Proteínas , SARS-CoV-2/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismo
9.
Sci Rep ; 12(1): 5257, 2022 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-35347170

RESUMEN

Numerous studies have shown a strong correlation between the number of neurofibrillary tangles of the tau protein and Alzheimer's disease progression, making the quantitative detection of tau very promising from a clinical point of view. However, the lack of highly reliable fluorescent probes for selective imaging of tau neurofibrillary tangles is a major challenge due to sharing similar ß-sheet motifs with homologous Amyloid-ß fibrils. In the current work, we describe the rational design and the in silico evaluation of a small-size focused library of fluorescent probes, consisting of a BODIPY core (electron acceptor) featuring highly conjugated systems (electron donor) with a length in the range 13-19 Å at C3. Among the most promising probes in terms of binding mode, theoretical affinity and polarity, BT1 has been synthesized and tested in vitro onto human induced pluripotent stem cells derived neuronal cell cultures. The probe showed excellent photophysical properties and high selectivity allowing in vitro imaging of hyperphosphorylated tau protein filaments with minimal background noise. Our findings offer new insight into the structure-activity relationship of this class of tau selective fluorophores, paving the way for boosting tau tangle detection in patients possibly through retinal spectral scans.


Asunto(s)
Células Madre Pluripotentes Inducidas , Compuestos de Boro , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Neuronas/metabolismo , Proteínas tau/metabolismo
10.
Commun Biol ; 5(1): 20221, 2022 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-34992214

RESUMEN

As the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic continues to spread, several variants of the virus, with mutations distributed all over the viral genome, are emerging. While most of the variants present mutations having little to no effects at the phenotypic level, some of these variants are spreading at a rate that suggests they may present a selective advantage. In particular, these rapidly spreading variants present specific mutations on the spike protein. These observations call for an urgent need to characterize the effects of these variants' mutations on phenotype features like contagiousness and antigenicity. With this aim, we performed molecular dynamics simulations on a selected set of possible spike variants in order to assess the stabilizing effect of particular amino acid substitutions on the molecular complex. We specifically focused on the mutations that are both characteristic of the top three most worrying variants at the moment, i.e the English, South African, and Amazonian ones, and that occur at the molecular interface between SARS-CoV-2 spike protein and its human ACE2 receptor. We characterize these variants' effect in terms of (i) residue mobility, (ii) compactness, studying the network of interactions at the interface, and (iii) variation of shape complementarity via expanding the molecular surfaces in the Zernike basis. Overall, our analyses highlighted greater stability of the three variant complexes with respect to both the wild type and two negative control systems, especially for the English and Amazonian variants. In addition, in the three variants, we investigate the effects a not-yet observed mutation in position 501 could provoke on complex stability. We found that a phenylalanine mutation behaves similarly to the English variant and may cooperate in further increasing the stability of the South African one, hinting at the need for careful surveillance for the emergence of these mutations in the population. Ultimately, we show that the proposed observables describe key features for the stability of the ACE2-spike complex and can help to monitor further possible spike variants.


Asunto(s)
Sustitución de Aminoácidos , Enzima Convertidora de Angiotensina 2/genética , Mutación , SARS-CoV-2/fisiología , Enzima Convertidora de Angiotensina 2/química , Enzima Convertidora de Angiotensina 2/metabolismo , Simulación de Dinámica Molecular , Unión Proteica
11.
Biomolecules ; 11(10)2021 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-34680172

RESUMEN

Aldehydes are a class of carbonyl compounds widely used as intermediates in the pharmaceutical, cosmetic and food industries. To date, there are few fully enzymatic methods for synthesizing these highly reactive chemicals. In the present work, we explore the biocatalytic potential of an amino oxidase extracted from the etiolated shoots of Lathyrus cicera for the synthesis of value-added aldehydes, starting from the corresponding primary amines. In this frame, we have developed a completely chromatography-free purification protocol based on crossflow ultrafiltration, which makes the production of this enzyme easily scalable. Furthermore, we determined the kinetic parameters of the amine oxidase toward 20 differently substituted aliphatic and aromatic primary amines, and we developed a biocatalytic process for their conversion into the corresponding aldehydes. The reaction occurs in aqueous media at neutral pH in the presence of catalase, which removes the hydrogen peroxide produced during the reaction itself, contributing to the recycling of oxygen. A high conversion (>95%) was achieved within 3 h for all the tested compounds.


Asunto(s)
Aldehídos/síntesis química , Amina Oxidasa (conteniendo Cobre)/química , Aminas/química , Lathyrus/química , Amina Oxidasa (conteniendo Cobre)/genética , Amina Oxidasa (conteniendo Cobre)/aislamiento & purificación , Biocatálisis , Concentración de Iones de Hidrógeno , Cinética , Lathyrus/enzimología , Brotes de la Planta/química , Brotes de la Planta/enzimología
12.
J Nanobiotechnology ; 19(1): 172, 2021 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-34107976

RESUMEN

BACKGROUND: In recent years, the use of ferritins as nano-vehicles for drug delivery is taking center stage. Compared to other similar nanocarriers, Archaeoglobus fulgidus ferritin is particularly interesting due to its unique ability to assemble-disassemble under very mild conditions. Recently this ferritin was engineered to get a chimeric protein targeted to human CD71 receptor, typically overexpressed in cancer cells. RESULTS: Archaeoglobus fulgidus chimeric ferritin was used to generate a self-assembling hybrid nanoparticle hosting an aminic dendrimer together with a small nucleic acid. The positively charged dendrimer can indeed establish electrostatic interactions with the chimeric ferritin internal surface, allowing the formation of a protein-dendrimer binary system. The 4 large triangular openings on the ferritin shell represent a gate for negatively charged small RNAs, which access the internal cavity attracted by the dense positive charge of the dendrimer. This ternary protein-dendrimer-RNA system is efficiently uptaken by acute myeloid leukemia cells, typically difficult to transfect. As a proof of concept, we used a microRNA whose cellular delivery and induced phenotypic effects can be easily detected. In this article we have demonstrated that this hybrid nanoparticle successfully delivers a pre-miRNA to leukemia cells. Once delivered, the nucleic acid is released into the cytosol and processed to mature miRNA, thus eliciting phenotypic effects and morphological changes similar to the initial stages of granulocyte differentiation. CONCLUSION: The results here presented pave the way for the design of a new family of protein-based transfecting agents that can specifically target a wide range of diseased cells.


Asunto(s)
Dendrímeros/química , Sistemas de Liberación de Medicamentos/métodos , Ferritinas/química , Leucemia Mieloide/tratamiento farmacológico , Nanopartículas/química , Ácidos Nucleicos/química , Antígenos CD , Archaeoglobus fulgidus/genética , Archaeoglobus fulgidus/metabolismo , Línea Celular Tumoral , Ferritinas/genética , Humanos , MicroARNs/química , MicroARNs/farmacología , Receptores de Transferrina
13.
Comput Struct Biotechnol J ; 19: 3006-3014, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34002118

RESUMEN

Since the beginning of the Covid19 pandemic, many efforts have been devoted to identifying approaches to neutralize SARS-CoV-2 replication within the host cell. A promising strategy to block the infection consists of using a mutant of the human receptor angiotensin-converting enzyme 2 (ACE2) as a decoy to compete with endogenous ACE2 for the binding to the SARS-CoV-2 Spike protein, which decreases the ability of the virus to enter the host cell. Here, using a computational framework based on the 2D Zernike formalism we investigate details of the molecular binding and evaluate the changes in ACE2-Spike binding compatibility upon mutations occurring in the ACE2 side of the molecular interface. We demonstrate the efficacy of our method by comparing our results with experimental binding affinities changes upon ACE2 mutations, separating ones that increase or decrease binding affinity with an Area Under the ROC curve ranging from 0.66 to 0.93, depending on the magnitude of the effects analyzed. Importantly, the iteration of our approach leads to the identification of a set of ACE2 mutants characterized by an increased shape complementarity with Spike. We investigated the physico-chemical properties of these ACE2 mutants and propose them as bona fide candidates for Spike recognition.

14.
Bioconjug Chem ; 32(6): 1105-1116, 2021 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-33978420

RESUMEN

Gene expression regulation by small interfering RNA (siRNA) holds promise in treating a wide range of diseases through selective gene silencing. However, successful clinical application of nucleic acid-based therapy requires novel delivery options. Herein, to achieve efficient delivery of negatively charged siRNA duplexes, the internal cavity of "humanized" chimeric Archaeal ferritin (HumAfFt) was specifically decorated with novel cationic piperazine-based compounds (PAs). By coupling these rigid-rod-like amines with thiol-reactive reagents, chemoselective conjugation was efficiently afforded on topologically selected cysteine residues properly located inside HumAfFt. The capability of PAs-HumAfFt to host and deliver siRNA molecules through human transferrin receptor (TfR1), overexpressed in many cancer cells, was explored. These systems allowed siRNA delivery into HeLa, HepG2, and MCF-7 cancer cells with improved silencing effect on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene expression with respect to traditional transfection methodologies and provided a promising TfR1-targeting system for multifunctional siRNA delivery to therapeutic applications.


Asunto(s)
Portadores de Fármacos/química , Portadores de Fármacos/síntesis química , Diseño de Fármacos , Ferritinas/química , Piperazina/química , ARN Interferente Pequeño/química , Línea Celular Tumoral , Técnicas de Química Sintética , Humanos , ARN Interferente Pequeño/metabolismo
15.
Chemphyschem ; 22(11): 1134-1140, 2021 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-33794073

RESUMEN

Flavohemoglobins have the particular capability of binding unsaturated and cyclopropanated fatty acids as free acids or phospholipids. Fatty acid binding to the ferric heme results in a weak but direct bonding interaction. Ferrous and ferric protein, in presence or absence of a bound lipid molecule, have been characterized by transient absorption spectroscopy. Measurements have been also carried out both on the ferrous deoxygenated and on the CO bound protein to investigate possible long-range interaction between the lipid acyl chain moiety and the ferrous heme. After excitation of the deoxygenated derivatives the relaxation process reveals a slow dynamics (350 ps) in lipid-bound protein but is not observed in the lipid-free protein. The latter feature and the presence of an extra contribution in the absorption spectrum, indicates that the interaction of iron heme with the acyl chain moiety occurs only in the excited electronic state and not in the ground electronic state. Data analysis highlights the formation of a charge-transfer complex in which the iron ion of the lipid-bound protein in the expanded electronic excited state, possibly represented by a high spin Fe III intermediate, is able to bind to the sixth coordination ligand placed at a distance of at 3.5 Šfrom the iron. A very small nanosecond geminate rebinding is observed for CO adduct in lipid-free but not in the lipid-bound protein. The presence of the lipid thus appears to inhibit the mobility of CO in the heme pocket.


Asunto(s)
Proteínas Bacterianas/química , Escherichia coli/química , Hemoproteínas/química , Lípidos/química
16.
Front Mol Biosci ; 8: 607443, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33659275

RESUMEN

Despite the huge effort to contain the infection, the novel SARS-CoV-2 coronavirus has rapidly become pandemic, mainly due to its extremely high human-to-human transmission capability, and a surprisingly high viral charge of symptom-less people. While the seek for a vaccine is still ongoing, promising results have been obtained with antiviral compounds. In particular, lactoferrin is regarded to have beneficial effects both in preventing and soothing the infection. Here, we explore the possible molecular mechanisms with which lactoferrin interferes with SARS-CoV-2 cell invasion, preventing attachment and/or entry of the virus. To this aim, we search for possible interactions lactoferrin may have with virus structural proteins and host receptors. Representing the molecular iso-electron surface of proteins in terms of 2D-Zernike descriptors, we 1) identified putative regions on the lactoferrin surface able to bind sialic acid present on the host cell membrane, sheltering the cell from the virus attachment; 2) showed that no significant shape complementarity is present between lactoferrin and the ACE2 receptor, while 3) two high complementarity regions are found on the N- and C-terminal domains of the SARS-CoV-2 spike protein, hinting at a possible competition between lactoferrin and ACE2 for the binding to the spike protein.

17.
Comput Struct Biotechnol J ; 18: 2678-2686, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33101606

RESUMEN

Protein-protein interactions regulate almost all cellular functions and rely on a fine tune of surface amino acids properties involved on both molecular partners. The disruption of a molecular association can be caused even by a single residue mutation, often leading to a pathological modification of a biochemical pathway. Therefore the evaluation of the effects of amino acid substitutions on binding, and the ad hoc design of protein-protein interfaces, is one of the biggest challenges in computational biology. Here, we present a novel strategy for computational mutation and optimization of protein-protein interfaces. Modeling the interaction surface properties using the Zernike polynomials, we describe the shape and electrostatics of binding sites with an ordered set of descriptors, making possible the evaluation of complementarity between interacting surfaces. With a Monte Carlo approach, we obtain protein mutants with controlled molecular complementarities. Applying this strategy to the relevant case of the interaction between Ferritin and Transferrin Receptor, we obtain a set of Ferritin mutants with increased or decreased complementarity. The extensive molecular dynamics validation of the method results confirms its efficacy, showing that this strategy represents a very promising approach in designing correct molecular interfaces.

18.
Molecules ; 25(20)2020 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-33050326

RESUMEN

Resveratrol (3,5,4'-trihydroxystilbene) is a natural compound that can be found in high concentrations in red wine and in many typical foods found in human diet. Over the past decades, resveratrol has been widely investigated for its potential beneficial effects on human health. At the same time, numerous analytical methods have been developed for the quantitative determination of resveratrol isomers in oenological and food matrices. In the present work, we developed a very fast and sensitive GC-MS method for the determination of resveratrol in red wine based on ethylchloroformate derivatization. Since this reaction occurs directly in the water phase during the extraction process itself, it has the advantage of significantly reducing the overall processing time for the sample. This method presents low limits of quantification (LOQ) (25 ng/mL and 50 ng/mL for cis- and trans-resveratrol, respectively) and excellent accuracy and precision. Ethylchloroformate derivatization was successfully applied to the analysis of resveratrol isomers in a selection of 15 commercial Italian red wines, providing concentration values comparable to those reported in other studies. As this method can be easily extended to other classes of molecules present in red wine, it allows further development of new GC-MS methods for the molecular profiling of oenological matrices.


Asunto(s)
Ésteres del Ácido Fórmico/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Resveratrol/análisis , Resveratrol/química , Vino/análisis , Reproducibilidad de los Resultados
19.
Molecules ; 25(16)2020 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-32796621

RESUMEN

Extra virgin olive oil (EVOO) phenols represent a significant part of the intake of antioxidants and bioactive compounds in the Mediterranean diet. In particular, hydroxytyrosol (HTyr), tyrosol (Tyr), and the secoiridoids oleacein and oleocanthal play central roles as anti-inflammatory, neuro-protective and anti-cancer agents. These compounds cannot be easily obtained via chemical synthesis, and their isolation and purification from EVOO is cumbersome. Indeed, both processes involve the use of large volumes of organic solvents, hazardous reagents and several chromatographic steps. In this work we propose a novel optimized procedure for the green extraction, isolation and purification of HTyr, Tyr, oleacein and oleocanthal directly from EVOO, by using a Natural Deep Eutectic Solvent (NaDES) as an extracting phase, coupled with preparative high-performance liquid chromatography. This purification method allows the total recovery of the four components as single pure compounds directly from EVOO, in a rapid, economic and ecologically sustainable way, which utilizes biocompatible reagents and strongly limits the use or generation of hazardous substances.


Asunto(s)
Aldehídos/aislamiento & purificación , Fraccionamiento Químico/métodos , Cromatografía Líquida de Alta Presión/métodos , Monoterpenos Ciclopentánicos/aislamiento & purificación , Aceite de Oliva/química , Fenoles/aislamiento & purificación , Alcohol Feniletílico/análogos & derivados , Extractos Vegetales/aislamiento & purificación , Alcohol Feniletílico/aislamiento & purificación
20.
Int J Mol Sci ; 21(14)2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-32679799

RESUMEN

Proteins, as a major component of organisms, are considered the preferred biomaterials for drug delivery vehicles. Hemoglobin (Hb) has been recently rediscovered as a potential drug carrier, but its use for biomedical applications still lacks extensive investigation. To further explore the possibility of utilizing Hb as a potential tumor targeting drug carrier, we examined and compared the biodistribution of Hb in healthy and lung tumor-bearing mice, using for the first time 89Zr labelled Hb in a positron emission tomography (PET) measurement. Hb displays a very high conjugation yield in its fast and selective reaction with the maleimide-deferoxamine (DFO) bifunctional chelator. The high-resolution X-ray structure of the Hb-DFO complex demonstrated that cysteine ß93 is the sole attachment moiety to the αß-protomer of Hb. The Hb-DFO complex shows quantitative uptake of 89Zr in solution as determined by radiochromatography. Injection of 0.03 mg of Hb-DFO-89Zr complex in healthy mice indicates very high radioactivity in liver, followed by spleen and lungs, whereas a threefold increased dosage results in intensification of PET signal in kidneys and decreased signal in liver and spleen. No difference in biodistribution pattern is observed between naïve and tumor-bearing mice. Interestingly, the liver Hb uptake did not decrease upon clodronate-mediated macrophage depletion, indicating that other immune cells contribute to Hb clearance. This finding is of particular interest for rapidly developing clinical immunology and projects aiming to target, label or specifically deliver agents to immune cells.


Asunto(s)
Portadores de Fármacos/farmacocinética , Sistemas de Liberación de Medicamentos , Hemoglobinas/farmacocinética , Neoplasias Pulmonares/metabolismo , Pulmón/metabolismo , Animales , Línea Celular Tumoral , Complejos de Coordinación/química , Complejos de Coordinación/farmacocinética , Deferoxamina/análogos & derivados , Deferoxamina/farmacocinética , Portadores de Fármacos/química , Femenino , Hemoglobinas/química , Humanos , Ratones , Ratones Endogámicos BALB C , Modelos Moleculares , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radioisótopos/química , Radioisótopos/farmacocinética , Distribución Tisular , Circonio/química , Circonio/farmacocinética
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