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1.
J Med Chem ; 67(8): 6658-6672, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38569135

RESUMEN

BRD4 is associated with a variety of human diseases, including breast cancer. The crucial roles of amino-terminal bromodomains (BDs) of BRD4 in binding with acetylated histones to regulate oncogene expression make them promising drug targets. However, adverse events impede the development of the BD inhibitors. BRD4 adopts an extraterminal (ET) domain, which recruits proteins to drive oncogene expression. We discovered a peptide inhibitor PiET targeting the ET domain to disrupt BRD4/JMJD6 interaction, a protein complex critical in oncogene expression and breast cancer. The cell-permeable form of PiET, TAT-PiET, and PROTAC-modified TAT-PiET, TAT-PiET-PROTAC, potently inhibits the expression of BRD4/JMJD6 target genes and breast cancer cell growth. Combination therapy with TAT-PiET/TAT-PiET-PROTAC and JQ1, iJMJD6, or Fulvestrant exhibits synergistic effects. TAT-PiET or TAT-PiET-PROTAC treatment overcomes endocrine therapy resistance in ERα-positive breast cancer cells. Taken together, we demonstrated that targeting the ET domain is effective in suppressing breast cancer, providing a therapeutic avenue in the clinic.


Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Proteínas que Contienen Bromodominio , Proteínas de Ciclo Celular , Proliferación Celular , Factores de Transcripción , Humanos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Femenino , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/metabolismo , Proteínas de Ciclo Celular/antagonistas & inhibidores , Proteínas de Ciclo Celular/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Animales , Proliferación Celular/efectos de los fármacos , Péptidos/farmacología , Péptidos/química , Línea Celular Tumoral , Ratones , Dominios Proteicos , Ratones Desnudos , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/metabolismo
2.
Food Chem ; 448: 139157, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38569411

RESUMEN

About half of the world's population is infected with the bacterium Helicobacter pylori. For colonization, the bacterium neutralizes the low gastric pH and recruits immune cells to the stomach. The immune cells secrete cytokines, i.e., the pro-inflammatory IL-17A, which directly or indirectly damage surface epithelial cells. Since (I) dietary proteins are known to be digested into bitter tasting peptides in the gastric lumen, and (II) bitter tasting compounds have been demonstrated to reduce the release of pro-inflammatory cytokines through functional involvement of bitter taste receptors (TAS2Rs), we hypothesized that the sweet-tasting plant protein thaumatin would be cleaved into anti-inflammatory bitter peptides during gastric digestion. Using immortalized human parietal cells (HGT-1 cells), we demonstrated a bitter taste receptor TAS2R16-dependent reduction of a H. pylori-evoked IL-17A release by up to 89.7 ± 21.9% (p ≤ 0.01). Functional involvement of TAS2R16 was demonstrated by the study of specific antagonists and siRNA knock-down experiments.


Asunto(s)
Helicobacter pylori , Interleucina-17 , Proteínas de Plantas , Receptores Acoplados a Proteínas G , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Interleucina-17/metabolismo , Interleucina-17/genética , Interleucina-17/inmunología , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/química , Gusto , Digestión , Péptidos/farmacología , Péptidos/química , Péptidos/metabolismo , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/metabolismo , Infecciones por Helicobacter/inmunología , Línea Celular
3.
J Chromatogr A ; 1722: 464828, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38581973

RESUMEN

The linkages of disulfide bond (DSB) play important roles in protein stability and activity. Mass spectrometry-based (MS-based) techniques become accepted tools for DSB analysis in the recent decade. In the bottom-up approach, after enzyme digestion, the neighbouring amino acids of cysteines have great impacts on the physicochemical properties of resulting disulfide bond peptides, determining their retention behaviour on liquid chromatography (LC) and their MS ionization efficiency. In this study, the addition of supercharging reagent in LC mobile phase was used to examine the impact of supercharging reagent on the charge states of disulfide-bond peptides. The results showed that 0.1 % m-nitrobenzyl alcohol (m-NBA) in LC mobile phase increased the sensitivity and charge states of DSB peptides from our model protein, equine Interleukin-5 (eIL5), as well as the resolution of reversed-phase chromatography. Notably, also the sensitivity of C-terminal peptide with His-tag significantly improved. Our findings highlight the effectiveness of employing m-NBA as a supercharging reagent when investigating disulfide-linked peptides and the C-terminal peptide with a His-tag through nano-liquid chromatography mass spectrometry.


Asunto(s)
Alcoholes Bencílicos , Disulfuros , Péptidos , Disulfuros/química , Alcoholes Bencílicos/química , Alcoholes Bencílicos/aislamiento & purificación , Péptidos/química , Péptidos/aislamiento & purificación , Animales , Caballos , Histidina/química , Cromatografía Liquida/métodos , Cromatografía de Fase Inversa/métodos , Cromatografía Líquida de Alta Presión/métodos
4.
J Chem Inf Model ; 64(8): 3430-3442, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38588472

RESUMEN

Peptide dendrimers are a type of branched, symmetric, and topologically well-defined molecule that have already been used as delivery systems for nucleic acid transfection. Several of the most promising sequences showed high efficiency in many key steps of transfection, namely, binding siRNA, entering cells, and evading the endosome. However, small changes to the peptide dendrimers, such as in the hydrophobic core, the amino acid chirality, or the total available charges, led to significantly different experimental results with unclear mechanistic insights. In this work, we built a computational model of several of those peptide dendrimers (MH18, MH13, and MH47) and some of their variants to study the molecular details of the structure and function of these molecules. We performed CpHMD simulations in the aqueous phase and in interaction with a lipid bilayer to assess how conformation and protonation are affected by pH in different environments. We found that while the different peptide dendrimer sequences lead to no substantial structural differences in the aqueous phase, the total charge and, more importantly, the total charge density are key for the capacity of the dendrimer to interact and destabilize the membrane. These dendrimers become highly charged when the pH changes from 7.5 to 4.5, and the presence of a high charge density, which is decreased for MH47 that has four fewer titratable lysines, is essential to trigger membrane destabilization. These findings are in excellent agreement with the experimental data and help us to understand the high efficiency of some dendrimers and why the dendrimer MH47 is unable to complete the transfection process. This evidence provides further understanding of the mode of action of these peptide dendrimers and will be pivotal for the future design of new sequences with improved transfection capabilities.


Asunto(s)
Dendrímeros , Endosomas , Péptidos , Dendrímeros/química , Endosomas/metabolismo , Péptidos/química , Péptidos/metabolismo , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Simulación de Dinámica Molecular , Concentración de Iones de Hidrógeno , Electricidad Estática , Modelos Moleculares
5.
J Nat Prod ; 87(4): 1075-1083, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38591246

RESUMEN

Cinnamoyl moiety containing nonribosomal peptides represented by pepticinnamin E are a growing family of natural products isolated from different Streptomyces species and possess diverse bioactivities. The soil bacterium Streptomyces mirabilis P8-A2 harbors a cryptic pepticinnamin biosynthetic gene cluster, producing azodyrecins as major products. Inactivation of the azodyrecin biosynthetic gene cluster by CRISPR-BEST base editing led to the activation and production of pepticinnamin E (1) and its analogues, pepticinnamins N, O, and P (2-4), the structures of which were determined by detailed NMR spectroscopy, HRMS data, and Marfey's reactions. These new compounds did not show a growth inhibitory effect against the LNCaP and C4-2B prostate cancer lines, respectively.


Asunto(s)
Microbiología del Suelo , Streptomyces , Streptomyces/química , Estructura Molecular , Humanos , Familia de Multigenes , Péptidos/química , Péptidos/farmacología , Péptidos/aislamiento & purificación , Línea Celular Tumoral
6.
J Phys Chem B ; 128(15): 3605-3613, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38592238

RESUMEN

Since Hofmeister's seminal studies in the late 19th century, it has been known that salts and buffers can drastically affect the properties of peptides and proteins. These Hofmeister effects can be conceived of in terms of three distinct phenomena/mechanisms: water-salt interactions that indirectly induce the salting-out of a protein by water sequestration by the salt, and direct salt-protein interactions that can either salt-in or salt-out the protein. Unfortunately, direct salt-protein interactions responsible for Hofmeister effects are weak and difficult to quantify. As such, they are frequently construed of as being nonspecific. Nevertheless, there has been considerable effort to better specify these interactions. Here, we use pentapeptides to demonstrate the utility of the H-dimension of nuclear magnetic resonance (NMR) spectroscopy to assess anion binding using N-H signal shifts. We qualify binding using these, demonstrating the upfield shifts induced by anion association and revealing how they are much larger than the corresponding downfield shifts induced by magnetic susceptibility and other ionic strength change effects. We also qualify binding in terms of how the pattern of signal shifts changes with point mutations. In general, we find that the observed upfield shifts are small compared with those induced by anion binding to amide-based hosts, and MD simulations suggest that this is so. Thus, charge-diffuse anions associate mostly with the nonpolar regions of the peptide rather than directly interacting with the amide N-H groups. These findings reveal the utility of 1H NMR spectroscopy for qualifying affinity to peptides─even when affinity constants are very low─and serve as a benchmark for using NMR spectroscopy to study anion binding to more complex systems.


Asunto(s)
Péptidos , Proteínas , Péptidos/química , Aniones/química , Proteínas/química , Amidas/química , Cloruro de Sodio , Agua
7.
J Chromatogr A ; 1722: 464830, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38608366

RESUMEN

Development of meaningful and reliable analytical assays in the (bio)pharmaceutical industry can often be challenging, involving tedious trial and error experimentation. In this work, an automated analytical workflow using an AI-based algorithm for streamlined method development and optimization is presented. Chromatographic methods are developed and optimized from start to finish by a feedback-controlled modeling approach using readily available LC instrumentation and software technologies, bypassing manual user intervention. With the use of such tools, the time requirement of the analyst is drastically minimized in the development of a method. Herein key insights on chromatography system control, automatic optimization of mobile phase conditions, and final separation landscape for challenging multicomponent mixtures are presented (e.g., small molecules drug, peptides, proteins, and vaccine products) showcased by a detailed comparison of a chiral method development process. The work presented here illustrates the power of modern chromatography instrumentation and AI-based software to accelerate the development and deployment of new separation assays across (bio)pharmaceutical modalities while yielding substantial cost-savings, method robustness, and fast analytical turnaround.


Asunto(s)
Programas Informáticos , Cromatografía Liquida/métodos , Algoritmos , Péptidos/análisis , Péptidos/química , Proteínas/análisis , Preparaciones Farmacéuticas/análisis , Preparaciones Farmacéuticas/química , Inteligencia Artificial , Vacunas/química , Vacunas/análisis , Retroalimentación
8.
J Nanobiotechnology ; 22(1): 198, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38649957

RESUMEN

Heat shock protein 90 (HSP90) is overexpressed in numerous cancers, promotes the maturation of numerous oncoproteins and facilitates cancer cell growth. Certain HSP90 inhibitors have entered clinical trials. Although less than satisfactory clinical effects or insurmountable toxicity have compelled these trials to be terminated or postponed, these results of preclinical and clinical studies demonstrated that the prospects of targeting therapeutic strategies involving HSP90 inhibitors deserve enough attention. Nanoparticulate-based drug delivery systems have been generally supposed as one of the most promising formulations especially for targeting strategies. However, so far, no active targeting nano-formulations have succeeded in clinical translation, mainly due to complicated preparation, complex formulations leading to difficult industrialization, incomplete biocompatibility or nontoxicity. In this study, HSP90 and CD44-targeted A6 peptide functionalized biomimetic nanoparticles (A6-NP) was designed and various degrees of A6-modification on nanoparticles were fabricated to evaluate targeting ability and anticancer efficiency. With no excipients, the hydrophobic HSP90 inhibitor G2111 and A6-conjugated human serum albumin could self-assemble into nanoparticles with a uniform particle size of approximately 200 nm, easy fabrication, well biocompatibility and avoidance of hepatotoxicity. Besides, G2111 encapsulated in A6-NP was only released less than 5% in 12 h, which may avoid off-target cell toxicity before entering into cancer cells. A6 peptide modification could significantly enhance uptake within a short time. Moreover, A6-NP continues to exert the broad anticancer spectrum of Hsp90 inhibitors and displays remarkable targeting ability and anticancer efficacy both in hematological malignancies and solid tumors (with colon tumors as the model cancer) both in vitro and in vivo. Overall, A6-NP, as a simple, biomimetic and active dual-targeting (CD44 and HSP90) nanomedicine, displays high potential for clinical translation.


Asunto(s)
Antineoplásicos , Neoplasias del Colon , Proteínas HSP90 de Choque Térmico , Receptores de Hialuranos , Leucemia Mieloide Aguda , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Receptores de Hialuranos/metabolismo , Animales , Línea Celular Tumoral , Ratones , Neoplasias del Colon/tratamiento farmacológico , Antineoplásicos/farmacología , Antineoplásicos/química , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/metabolismo , Nanopartículas/química , Sistemas de Liberación de Medicamentos/métodos , Ratones Desnudos , Ratones Endogámicos BALB C , Péptidos/química , Péptidos/farmacología
9.
Mar Drugs ; 22(4)2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38667757

RESUMEN

Hypertension, a major health concern linked to heart disease and premature mortality, has prompted a search for alternative treatments due to side effects of existing medications. Sustainable harvesting of low-trophic marine organisms not only enhances food security but also provides a variety of bioactive molecules, including peptides. Despite comprising only a fraction of active natural compounds, peptides are ideal for drug development due to their size, stability, and resistance to degradation. Our review evaluates the anti-hypertensive properties of peptides and proteins derived from selected marine invertebrate phyla, examining the various methodologies used and their application in pharmaceuticals, supplements, and functional food. A considerable body of research exists on the anti-hypertensive effects of certain marine invertebrates, yet many species remain unexamined. The array of assessments methods, particularly for ACE inhibition, complicates the comparison of results. The dominance of in vitro and animal in vivo studies indicates a need for more clinical research in order to transition peptides into pharmaceuticals. Our findings lay the groundwork for further exploration of these promising marine invertebrates, emphasizing the need to balance scientific discovery and marine conservation for sustainable resource use.


Asunto(s)
Antihipertensivos , Organismos Acuáticos , Suplementos Dietéticos , Alimentos Funcionales , Péptidos , Animales , Antihipertensivos/farmacología , Antihipertensivos/química , Péptidos/farmacología , Péptidos/química , Humanos , Hipertensión/tratamiento farmacológico , Invertebrados , Productos Biológicos/farmacología , Productos Biológicos/química
10.
Mar Drugs ; 22(4)2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38667773

RESUMEN

The industrial processing of Argentine shortfin squid to obtain rings generates a significant amount of protein-rich waste, including the skin, which is rich in collagen and attached myofibrillar proteins. This waste is generally discarded. In this study, skin was used as a source of proteins that were hydrolysed using Trypsin, Esperase® or Alcalase®, which released peptides with antioxidant potential and, in particular, antihypertensive (ACE inhibition), hypoglycemic (DPP-IV inhibition) and/or nootropic (PEP inhibition) potential. Among the three enzymes tested, Esperase® and Alcalase produced hydrolysates with potent ACE-, DPP-IV- and PEP-inhibiting properties. These hydrolysates underwent chromatography fractionation, and the composition of the most bioactive fractions was analysed using HPLC-MS-MS. The fractions with the highest bioactivity exhibited very low IC50 values (16 and 66 µg/mL for ACE inhibition, 97 µg/mL for DPP-IV inhibition and 55 µg/mL for PEP inhibition) and were mainly derived from the hydrolysate obtained using Esperase®. The presence of Leu at the C-terminal appeared to be crucial for the ACE inhibitory activity of these fractions. The DPP-IV inhibitory activity of peptides seemed to be determined by the presence of Pro or Ala in the second position from the N-terminus, and Gly and/or Pro in the last C-terminal positions. Similarly, the presence of Pro in the peptides present in the best PEP inhibitory fraction seemed to be important in the inhibitory effect. These results demonstrate that the skin of the Argentine shortfin squid is a valuable source of bioactive peptides, suitable for incorporation into human nutrition as nutraceuticals and food supplements.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina , Decapodiformes , Inhibidores de la Dipeptidil-Peptidasa IV , Péptidos , Animales , Decapodiformes/química , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/aislamiento & purificación , Péptidos/química , Péptidos/farmacología , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Inhibidores de la Dipeptidil-Peptidasa IV/química , Hidrólisis , Hidrolisados de Proteína/química , Hidrolisados de Proteína/farmacología , Dipeptidil Peptidasa 4/química , Dipeptidil Peptidasa 4/metabolismo , Piel , Espectrometría de Masas en Tándem , Cromatografía Líquida de Alta Presión , Antioxidantes/farmacología , Antioxidantes/química
11.
Nat Commun ; 15(1): 2711, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38565864

RESUMEN

Regulatory arrest peptides interact with specific residues on bacterial ribosomes and arrest their own translation. Here, we analyse over 30,000 bacterial genome sequences to identify additional Sec/YidC-related arrest peptides, followed by in vivo and in vitro analyses. We find that Sec/YidC-related arrest peptides show patchy, but widespread, phylogenetic distribution throughout the bacterial domain. Several of the identified peptides contain distinct conserved sequences near the C-termini, but are still able to efficiently stall bacterial ribosomes in vitro and in vivo. In addition, we identify many arrest peptides that share an R-A-P-P-like sequence, suggesting that this sequence might serve as a common evolutionary seed to overcome ribosomal structural differences across species.


Asunto(s)
Proteínas de Escherichia coli , Biosíntesis de Proteínas , Filogenia , Péptidos/química , Ribosomas/genética , Ribosomas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas de Escherichia coli/metabolismo
12.
J Am Chem Soc ; 146(15): 10331-10341, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38573124

RESUMEN

Disruption of protein-protein interactions is medicinally important. Interface helices may be mimicked in helical probes featuring enhanced rigidities, binding to protein targets, stabilities in serum, and cell uptake. This form of mimicry is dominated by stapling between side chains of helical residues: there has been less progress on helical N-caps, and there were no generalizable C-caps. Conversely, in natural proteins, helicities are stabilized and terminated by C- and N-caps but not staples. Bicyclic caps previously introduced by us enable interface helical mimicry featuring rigid synthetic caps at both termini in this work. An unambiguously helical dual-capped system proved to be conformationally stable, binding cyclins A and E, and showed impressive cellular uptake. In addition, the dual-capped mimic was completely resistant to proteolysis in serum over an extended period when compared with "gold standard" hydrocarbon-stapled controls. Dual-capped peptidomimetics are a new, generalizable paradigm for helical interface probe design.


Asunto(s)
Péptidos , Péptidos/química , Estructura Secundaria de Proteína , Proteolisis
13.
Zhongguo Zhong Yao Za Zhi ; 49(3): 661-670, 2024 Feb.
Artículo en Chino | MEDLINE | ID: mdl-38621870

RESUMEN

Scorpions, a group of oldest animals with wide distribution in the world, have a long history of medicinal use. Scorpio, the dried body of Buthus martensii, is a rare animal medicine mainly used for the treatment of liver diseases, spasm, and convulsions in children in China. The venom has been considered as the active substance of scorpions. However, little is known about the small molecules in the venom of scorpions. According to the articles published in recent years, scorpions contain amino acids, fatty acids, steroids, and alkaloids, which endow scorpions with antimicrobial, anticoagulant, metabolism-regulating, and antitumor activities. This paper summarizes the small molecule chemical components and pharmacological activities of scorpions, with a view to providing valuable information for the discovery of new active molecules and the clinical use of scorpions.


Asunto(s)
Animales Venenosos , Antiinfecciosos , Venenos de Escorpión , Animales , Niño , Humanos , Péptidos/química , Escorpiones/química , Escorpiones/metabolismo , ADN Complementario , Venenos de Escorpión/farmacología
14.
ACS Appl Mater Interfaces ; 16(15): 18268-18284, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38564419

RESUMEN

The essential amino acid histidine plays a central role in the manifestation of several metabolic processes, including protein synthesis, enzyme-catalysis, and key biomolecular interactions. However, excess accumulation of histidine causes histidinemia, which shows brain-related medical complications, and the molecular mechanism of such histidine-linked complications is largely unknown. Here, we show that histidine undergoes a self-assembly process, leading to the formation of amyloid-like cytotoxic and catalytically active nanofibers. The kinetics of histidine self-assembly was favored in the presence of Mg(II) and Co(II) ions. Molecular dynamics data showed that preferential noncovalent interactions dominated by H-bonds between histidine molecules facilitate the formation of histidine nanofibers. The histidine nanofibers induced amyloid cross-seeding reactions in several proteins and peptides including pathogenic Aß1-42 and brain extract components. Further, the histidine nanofibers exhibited oxidase activity and enhanced the oxidation of neurotransmitters. Cell-based studies confirmed the cellular internalization of histidine nanofibers in SH-SY5Y cells and subsequent cytotoxic effects through necrosis and apoptosis-mediated cell death. Since several complications including behavioral abnormality, developmental delay, and neurological disabilities are directly linked to abnormal accumulation of histidine, our findings provide a foundational understanding of the mechanism of histidine-related complications. Further, the ability of histidine nanofibers to catalyze amyloid seeding and oxidation reactions is equally important for both biological and materials science research.


Asunto(s)
Nanofibras , Nanoestructuras , Neuroblastoma , Humanos , Histidina , Péptidos/química , Nanofibras/química , Amiloide/química , Péptidos beta-Amiloides/química
15.
ACS Appl Mater Interfaces ; 16(15): 18474-18489, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38581548

RESUMEN

The development of 2D or 3D bioactive platforms for rapidly isolating pure populations of cells from adult stem cells holds promise for advancing the understanding of cellular mechanisms, drug testing, and tissue engineering. Over the years, methods have emerged to synthesize bioactive micro- and nanostructured 2D materials capable of directing stem cell fate. We introduce a novel method for randomly micro- or nanopatterning any protein/peptide onto both 2D and 3D scaffolds via spray technology. Our goal is to investigate the impact of arranging bioactive micropatterns (ordered vs disordered) on surfaces to guide human mesenchymal stem cell (hMSC) differentiation. The spray technology efficiently coats materials with controlled, cost-effective bioactive micropatterns in various sizes and shapes. BMP-2 mimetic peptides were covalently grafted, individually or in combination with RGD peptides, onto activated polyethylene terephthalate (PET) surfaces through a spraying process, incorporating nano/microscale parameters like size, shape, and composition. The study explores different peptide distributions on surfaces and various peptide combinations. Four surfaces were homogeneously functionalized with these peptides (M1 to M4 with various densities of peptides), and six surfaces with disordered micro- and nanopatterns of peptides (S0 to S5 with different sizes of peptide patterns) were synthesized. Fluorescence microscopy assessed peptide distribution, followed by hMSC culture for 2 weeks, and evaluated osteogenic differentiation via immunocytochemistry and RT-qPCR for osteoblast and osteocyte markers. Cells on uniformly peptide-functionalized surfaces exhibited cuboidal forms, while those on surfaces with disordered patterns tended toward columnar or cuboidal shapes. Surfaces S4 and S5 showed dendrite-like formations resembling an osteocyte morphology. S5 showed significant overexpression of osteoblast (OPN) and osteocyte markers (E11, DMP1, and SOST) compared to control surfaces and other micropatterned surfaces. Notably, despite sharing an equivalent quantity of peptides with a homogeneous functionalized surface, S5 displayed a distinct distribution of peptides, resulting in enhanced osteogenic differentiation of hMSCs.


Asunto(s)
Células Madre Mesenquimatosas , Osteogénesis , Adulto , Humanos , Señales (Psicología) , Ligandos , Diferenciación Celular , Péptidos/química , Células Madre
16.
J Org Chem ; 89(8): 5511-5517, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38592436

RESUMEN

A CSD search in the Cambridge Crystallographic Database for the substructure N-CαH-C'(═O)-N gave 24,180 peptide structures for analysis of the pyramidalization of the sp2-hybridized carboxamide group C'(═O)NCα, which had not been investigated before. The dependence of the pyramidalization θ = O-N-C'-Cα on the rotation angle ψ = O═C'-Cα-N about bond C'-Cα resulted in a curve with three maxima, three minima, and six zero-crossings. Surprisingly, the ψ/θ analysis of the individual amino acid building blocks showed that all of them exhibited similar curves, irrespective of their different R substituents. This unusual behavior is explained by a 3-fold short-range potential set up by the three covalent bonds, emanating from Cα. The tie-up of the rotation angle ψ and the pyramidalization θ in a rigid coupling is remarkable. In the 24,180 peptide structures, subjected to X-ray crystallography, there is no dynamics. For peptides in solution, the rotation/pyramidalization curve ψ/θav determines the degree of pyramidalization θ, when the rotation angle ψ runs through a full 360° circle. Density functional theory (DFT) calculations of alaninamide supported the analysis.


Asunto(s)
Aminoácidos , Péptidos , Péptidos/química , Aminoácidos/química , Cristalografía por Rayos X
17.
Anal Chim Acta ; 1304: 342538, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38637049

RESUMEN

BACKGROUND: With the advent of proline-based reporter isobaric Tandem Mass Tag (TMTpro) reagents, the sample multiplexing capacity of tandem mass tags (TMTs) has been expanded, and up to 18 samples can be quantified in a multiplexed manner. Like classic TMT reagents, TMTpro reagents contain a tertiary amine group, which markedly enhances their reactivity toward hydroxyl groups and results in O-acylation of serine, threonine and tyrosine residues. This overlabeling significantly compromises proteome analysis in terms of depth and precision. In particular, the reactivity of hydroxyl-containing residues can be dramatically enhanced when coexisting with a histidine in the same peptides, leading to a severe systematic bias against the analysis of these peptides. Although some protocols using a reduced molar excess of TMT under alkaline conditions can alleviate overlabeling of histidine-free peptides to some extent, they have a limited effect on histidyl- and hydroxyl-containing peptides. RESULTS: Here, we report a novel TMTpro labeling method that overcomes detrimental overlabeling while providing high labeling efficiency of amines. Additionally, our method is cost-effective, as it requires only half the amount of TMTpro reagents recommended by the reagent manufacturer. In a deep-scale analysis of a yeast/human two-proteome model sample, we compared our method with a typical alkaline labeling method using a reduced molar excess of TMTpro. Even at a depth of over 10,000 proteins, our method detected 23.7% more unique peptides and 8.7% more protein groups compared to the alkaline labeling method. Moreover, our method significantly improved the quantitative precision due to the reduced variability in labeling and increased protein sequence coverage. This substantially enhanced the statistical power of our method for detecting differentially abundant proteins, providing an average of 13% more yeast proteins that reached statistical significance. SIGNIFCANCE: We presented a novel TMTpro labeling method that overcomes the detrimental O-acylation and thus significantly improves the depth and quantitative precision for proteome analysis.


Asunto(s)
Proteoma , Espectrometría de Masas en Tándem , Humanos , Proteoma/análisis , Espectrometría de Masas en Tándem/métodos , Proteómica/métodos , Péptidos/química , Aminas , Acilación
18.
J Agric Food Chem ; 72(15): 8569-8580, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38563891

RESUMEN

Rice protein peptides (RPP) are a potentially valuable source of high-quality calcium chelating properties. However, there is a lack of information regarding the calcium-absorption-promoting effect of RPP and its underlying mechanism. The present study adopted molecular docking methodologies to analyze the 10 most potent peptide segments from RPP. Results revealed that the peptide AHVGMSGEEPE (AHV) displayed optimal calcium binding properties (calcium-chelating capacity 55.69 ± 0.66 mg/g). Quantum chemistry analysis revealed that the AHV peptide effectively binds and forms stable complexes with calcium via the carbonyl oxygen atoms in valine at position 3 and the carbonyl of the C-terminal carboxyl group of glutamate at position 11. The spectral analysis results indicated that AHV may bind to calcium through carboxyl oxygen atoms, resulting in a transition from a smooth surface block-like structure to a dense granular structure. Furthermore, this study demonstrated that the 4 mmol/L AHV-Ca chelate (61.75 ± 13.23 µg/well) significantly increases calcium absorption compared to 1 mM CaCl2 (28.57 ± 8.59 µg/well) in the Caco-2 cell monolayer. In terms of mechanisms, the novel peptide-calcium chelate AHV-Ca derived from RPP exerts a cell-level effect by upregulating the expression of TRPV6 calcium-ion-channel-related genes and proteins (TRPV6 and Calbindin-D9k). This study provides a theoretical basis for developing functional foods with the AHV peptide as ingredients to improve calcium absorption.


Asunto(s)
Calcio , Oryza , Humanos , Calcio/metabolismo , Células CACO-2 , Oryza/metabolismo , Simulación del Acoplamiento Molecular , Calcio de la Dieta/metabolismo , Péptidos/química , Oxígeno
19.
Phys Chem Chem Phys ; 26(15): 11880-11892, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38568008

RESUMEN

Recent experiments have revealed that adenosine triphosphate (ATP) suppresses the fibrillation of amyloid peptides - a process closely linked to neurodegenerative diseases such as Alzheimer's and Parkinson's. Apart from the adsorption of ATP onto amyloid peptides, the molecular understanding is still limited, leaving the underlying mechanism for the fibrillation suppression by ATP largely unclear, especially in regards to the molecular energetics. Here we provide an explanation at the molecular scale by quantifying the free energies using all-atom molecular dynamics simulations. We found that the changes of the free energies due to the addition of ATP lead to a significant equilibrium shift towards monomeric peptides in agreement with experiments. Despite ATP being a highly charged species, the decomposition of the free energies reveals that the van der Waals interactions with the peptide are decisive in determining the relative stabilization of the monomeric state. While the phosphate moiety exhibits strong electrostatic interactions, the compensation by the water solvent results in a minor, overall Coulomb contribution. Our quantitative analysis of the free energies identifies which intermolecular interactions are responsible for the suppression of the amyloid fibril formation by ATP and offers a promising method to analyze the roles of similarly complex cosolvents in aggregation processes.


Asunto(s)
Amiloide , Péptidos , Amiloide/química , Péptidos/química , Agua/química , Entropía , Solventes/química , Simulación de Dinámica Molecular , Proteínas Amiloidogénicas , Péptidos beta-Amiloides/química , Fragmentos de Péptidos/química
20.
Sci Rep ; 14(1): 7684, 2024 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-38561372

RESUMEN

Peptide toxins found in sea anemones venom have diverse properties that make them important research subjects in the fields of pharmacology, neuroscience and biotechnology. This study used high-throughput sequencing technology to systematically analyze the venom components of the tentacles, column, and mesenterial filaments of sea anemone Heteractis crispa, revealing the diversity and complexity of sea anemone toxins in different tissues. A total of 1049 transcripts were identified and categorized into 60 families, of which 91.0% were proteins and 9.0% were peptides. Of those 1049 transcripts, 416, 291, and 307 putative proteins and peptide precursors were identified from tentacles, column, and mesenterial filaments respectively, while 428 were identified when the datasets were combined. Of these putative toxin sequences, 42 were detected in all three tissues, including 33 proteins and 9 peptides, with the majority of peptides being ShKT domain, ß-defensin, and Kunitz-type. In addition, this study applied bioinformatics approaches to predict the family classification, 3D structures, and functional annotation of these representative peptides, as well as the evolutionary relationships between peptides, laying the foundation for the next step of peptide pharmacological activity research.


Asunto(s)
Venenos de Cnidarios , Anémonas de Mar , Animales , Humanos , Anémonas de Mar/metabolismo , Péptidos/química , Perfilación de la Expresión Génica , Venenos de Cnidarios/química
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