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1.
Cogn Emot ; 38(4): 411-417, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38874558

RESUMEN

Democratic societies have to face the challenge of increasing affective polarisation - a strong, emotionally fuelled, opposition between adherents of different political parties, or conflicting views and attitudes in different social groups. Social and psychological sciences can contribute to a better understanding of this phenomenon and the special role of emotion theory and research in this respect. In their invited contribution, Bakker and Lelkes note the lack of conceptual precision of the term affective and invite emotion scientists to fill this notion with a theoretical structure that encourages systematic research across different problem areas and cultures. Two invited comments on this article support this initiative but favour an approach that privileges discrete emotions. In his comment, Von Scheve argues that intentionality and the associated action tendencies are essential to understand the emotional basis of polarisation. Halperin et al., based on a conceptual analysis and their own empirical research, they highlight the multi-faceted emotion of disappointment, covering both negative and positive aspects, as the most promising candidate. Finally, I consider the potential role of mixed or blended emotions as well as the potential contributions of appraisal theory, especially with respect to appraisal bias and ensuing emotion dispositions and action tendencies.


Asunto(s)
Emociones , Política , Humanos , Teoría Psicológica
2.
Eur J Hum Genet ; 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38553610

RESUMEN

Voltage-gated L-type Cav1.3 Ca2+ channels support numerous physiological functions including neuronal excitability, sinoatrial node pacemaking, hearing, and hormone secretion. De novo missense mutations in the gene of their pore-forming α1-subunit (CACNA1D) induce severe gating defects which lead to autism spectrum disorder and a more severe neurological disorder with and without endocrine symptoms. The number of CACNA1D variants reported is constantly rising, but their pathogenic potential often remains unclear, which complicates clinical decision-making. Since functional tests are time-consuming and not always available, bioinformatic tools further improving pathogenicity potential prediction of novel variants are needed. Here we employed evolutionary analysis considering sequences of the Cav1.3 α1-subunit throughout the animal kingdom to predict the pathogenicity of human disease-associated CACNA1D missense variants. Co-variation analyses of evolutionary information revealed residue-residue couplings and allowed to generate a score, which correctly predicted previously identified pathogenic variants, supported pathogenicity in variants previously classified as likely pathogenic and even led to the re-classification or re-examination of 18 out of 80 variants previously assessed with clinical and electrophysiological data. Based on the prediction score, we electrophysiologically tested one variant (V584I) and found significant gating changes associated with pathogenic risks. Thus, our co-variation model represents a valuable addition to complement the assessment of the pathogenicity of CACNA1D variants completely independent of clinical diagnoses, electrophysiology, structural or biophysical considerations, and solely based on evolutionary analyses.

3.
Brain Inj ; 38(4): 260-266, 2024 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-38297434

RESUMEN

This study analyzed the linguistic and psychometric validation of the Japanese version of the Quality of Life after Brain Injury-Overall Scale (QOLIBRI-OS) consisting of six items which cover several TBI-relevant domains. We hypothesized that the Japanese version has good reliability, convergent validity, and divergent validity, compared with its long version, the 37-item QOLIBRI. The QOLIBRI-OS Japanese version was forward and back-translated from the English version. In total, 129 individuals participated in this study after experiencing a traumatic brain injury and attending clinics, rehabilitation centers, and support centers in Japan. The structure of the QOLIBRI-OS was investigated by confirmatory factor analyses and compared with the QOLIBRI. Only one factor was extracted, and a model with one underlying factor had a good fit. The QOLIBRI-OS showed good-to-excellent internal consistency and test-retest reliability. The QOLIBRI-OS was positively correlated with the QOLIBRI, Short Form Health Survey-36 version 2, and Glasgow Outcome Scale Extended, and negatively correlated with the Hospital Anxiety and Depression Scale. The results suggest that the QOLIBRI-OS Japanese version is a reliable and valid tool for assessing disease-specific health-related QOL in individuals after traumatic brain injury in Japan.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Lesiones Encefálicas , Humanos , Calidad de Vida , Japón , Reproducibilidad de los Resultados , Psicometría , Encuestas y Cuestionarios
4.
J Chem Theory Comput ; 20(5): 2321-2333, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38373307

RESUMEN

Protein folding is a fascinating, not fully understood phenomenon in biology. Molecular dynamics (MD) simulations are an invaluable tool to study conformational changes in atomistic detail, including folding and unfolding processes of proteins. However, the accuracy of the conformational ensembles derived from MD simulations inevitably relies on the quality of the underlying force field in combination with the respective water model. Here, we investigate protein folding, unfolding, and misfolding of fast-folding proteins by examining different force fields with their recommended water models, i.e., ff14SB with the TIP3P model and ff19SB with the OPC model. To this end, we generated long conventional MD simulations highlighting the perks and pitfalls of these setups. Using Markov state models, we defined kinetically independent conformational substates and emphasized their distinct characteristics, as well as their corresponding state probabilities. Surprisingly, we found substantial differences in thermodynamics and kinetics of protein folding, depending on the combination of the protein force field and water model, originating primarily from the different water models. These results emphasize the importance of carefully choosing the force field and the respective water model as they determine the accuracy of the observed dynamics of folding events. Thus, the findings support the hypothesis that the water model is at least equally important as the force field and hence needs to be considered in future studies investigating protein dynamics and folding in all areas of biophysics.


Asunto(s)
Pliegue de Proteína , Agua , Proteínas , Simulación de Dinámica Molecular , Conformación Molecular , Termodinámica , Conformación Proteica , Desplegamiento Proteico
5.
J Acoust Soc Am ; 155(1): 18-28, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-38169520

RESUMEN

In an earlier study, we analyzed how audio signals obtained from three professional opera singers varied when they sang one octave wide eight-tone scales in ten different emotional colors. The results showed systematic variations in voice source and long-term-average spectrum (LTAS) parameters associated with major emotion "families". For two of the singers, subglottal pressure (PSub) also was recorded, thus allowing analysis of an additional main physiological voice control parameter, glottal resistance (defined as the ratio between PSub and glottal flow), and related to glottal adduction. In the present study, we analyze voice source and LTAS parameters derived from the audio signal and their correlation with Psub and glottal resistance. The measured parameters showed a systematic relationship with the four emotion families observed in our previous study. They also varied systematically with values of the ten emotions along the valence, power, and arousal dimensions; valence showed a significant correlation with the ratio between acoustic voice source energy and subglottal pressure, while Power varied significantly with sound level and two measures related to the spectral dominance of the lowest spectrum partial. the fundamental.


Asunto(s)
Canto , Voz , Humanos , Calidad de la Voz , Voz/fisiología , Acústica , Glotis/fisiología
6.
J Gen Physiol ; 156(2)2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38175169

RESUMEN

Voltage-dependent and Ca2+-dependent inactivation (VDI and CDI, respectively) of CaV channels are two biologically consequential feedback mechanisms that fine-tune Ca2+ entry into neurons and cardiomyocytes. Although known to be initiated by distinct molecular events, how these processes obstruct conduction through the channel pore remains poorly defined. Here, focusing on ultrahighly conserved tryptophan residues in the interdomain interfaces near the selectivity filter of CaV1.3, we demonstrate a critical role for asymmetric conformational changes in mediating VDI and CDI. Specifically, mutagenesis of the domain III-IV interface, but not others, enhanced VDI. Molecular dynamics simulations demonstrate that mutations in distinct selectivity filter interfaces differentially impact conformational flexibility. Furthermore, mutations in distinct domains preferentially disrupt CDI mediated by the N- versus C-lobes of CaM, thus uncovering a scheme of structural bifurcation of CaM signaling. These findings highlight the fundamental importance of the asymmetric arrangement of the pseudotetrameric CaV pore domain for feedback inhibition.


Asunto(s)
Calcio , Simulación de Dinámica Molecular , Mutación , Miocitos Cardíacos , Neuronas
7.
J Chem Phys ; 160(1)2024 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-38180253

RESUMEN

Arising from the harmonic approximation in solving the vibrational Schrödinger equation, normal modes dissect molecular vibrations into distinct degrees of freedom. Normal modes are widely used as they give rise to descriptive vibrational notations and are convenient for expanding anharmonic potential energy surfaces as an alternative to higher-order Taylor series representations. Usually, normal modes are expressed in Cartesian coordinates, which bears drawbacks that can be overcome by switching to internal coordinates. Considering vibrational notations, normal modes with delocalized characters are difficult to denote, but internal coordinates offer a route to clearer notations. Based on the Hessian, normal mode decomposition schemes for a given set of internal coordinates can describe a normal mode by its contributions from internal coordinates. However, choosing a set of internal coordinates is not straightforward. While the Hessian provides unique sets of normal modes, various internal coordinate sets are possible for a given system. In the present work, we employ a normal mode decomposition scheme to choose an optimal set. Therefore, we screen reasonable sets based on topology and symmetry considerations and rely on a metric that minimizes coupling between internal coordinates. Ultimately, the Nomodeco toolkit presented here generates internal coordinate sets to find an optimal set for representing molecular vibrations. The resulting contribution tables can be used to clarify vibrational notations. We test our scheme on small to mid-sized molecules, showing how the space of definable internal coordinate sets can significantly be reduced.

8.
Expert Rev Gastroenterol Hepatol ; 17(12): 1205-1219, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38131269

RESUMEN

INTRODUCTION: The STRIDE consensus suggested to focus on mucosal healing, based on biomarkers and endoscopy, in addition to clinical endpoints as treatment target. This narrative review provides a critique of this concept in Crohn´s disease. AREAS COVERED: We analyze and discuss the limitations of endpoints as targets, their currently limited achievability, and the controversial evidence relating to 'treat to target.' The relevant publications in Pubmed were identified in a literature review with the key word 'Crohn´s disease.' EXPERT OPINION: All targets and endpoints have their limitations, and, even if reached, not all have unequivocally been shown to improve prognosis. The major deficiency of STRIDE is not only the lack of validation and agreement upon endpoints but little evidence of their achievability in a sizable proportion of patients by dose or timing adjustments or switching the medication. Above all, the concept should be based on clear evidence that patients indeed benefit from appropriate escalation of treatment and relevant controlled studies in this regard have been controversial. Until the STRIDE approach is proven to be superior to standard treatment focusing on clinical well-being, the field should remain reluctant and expect more convincing evidence before new targets are approved.


Asunto(s)
Enfermedad de Crohn , Humanos , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/tratamiento farmacológico
9.
Foods ; 12(21)2023 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-37959058

RESUMEN

Allergies related to kiwi consumption have become a growing health concern, with their prevalence on the rise. Many of these allergic reactions are attributed to cross-reactivity, particularly with the major allergen found in birch pollen. This cross-reactivity is associated with proteins belonging to the pathogenesis-related class 10 (PR-10) protein family. In our study, we determined the three-dimensional structures of the two PR-10 proteins in gold and green kiwi fruits, Act c 8 and Act d 8, using nuclear magnetic resonance (NMR) spectroscopy. The structures of both kiwi proteins closely resemble the major birch pollen allergen, Bet v 1, providing a molecular explanation for the observed immunological cross-reactivity between kiwi and birch pollen. Compared to Act d 11, however, a kiwi allergen that shares the same architecture as PR-10 proteins, structural differences are apparent. Moreover, despite both Act c 8 and Act d 8 containing multiple cysteine residues, no disulfide bridges are present within their structures. Instead, all the cysteines are accessible on the protein's surface and exposed to the surrounding solvent, where they are available for reactions with components of the natural food matrix. This structural characteristic sets Act c 8 and Act d 8 apart from other kiwi proteins with a high cysteine content. Furthermore, we demonstrate that pyrogallol, the most abundant phenolic compound found in kiwi, binds into the internal cavities of these two proteins, albeit with low affinity. Our research offers a foundation for further studies aimed at understanding allergic reactions associated with this fruit and exploring how interactions with the natural food matrix might be employed to enhance food safety.

10.
J Chem Inf Model ; 63(22): 7107-7123, 2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-37943023

RESUMEN

We evaluated a workflow to reliably sample the conformational space of a set of 47 peptidic macrocycles. Starting from SMILES strings, we use accelerated molecular dynamics simulations to overcome high energy barriers, in particular, the cis-trans isomerization of peptide bonds. We find that our approach performs very well in polar solvents like water and dimethyl sulfoxide. Interestingly, the protonation state of a secondary amine in the ring only slightly influences the conformational ensembles of our test systems. For several of the macrocycles, determining the conformational distribution in chloroform turns out to be considerably more challenging. Especially, the choice of partial charges crucially influences the ensembles in chloroform. We address these challenges by modifying initial structures and the choice of partial charges. Our results suggest that special care has to be taken to understand the configurational distribution in apolar solvents, which is a key step toward a reliable prediction of membrane permeation of macrocycles and their chameleonic properties.


Asunto(s)
Cloroformo , Péptidos , Solventes , Conformación Molecular , Péptidos/química , Simulación de Dinámica Molecular
11.
J Chem Inf Model ; 63(22): 6964-6971, 2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-37934909

RESUMEN

The electrostatic properties of proteins arise from the number and distribution of polar and charged residues. Electrostatic interactions in proteins play a critical role in numerous processes such as molecular recognition, protein solubility, viscosity, and antibody developability. Thus, characterizing and quantifying electrostatic properties of a protein are prerequisites for understanding these processes. Here, we present PEP-Patch, a tool to visualize and quantify the electrostatic potential on the protein surface in terms of surface patches, denoting separated areas of the surface with a common physical property. We highlight its applicability to elucidate protease substrate specificity and antibody-antigen recognition and predict heparin column retention times of antibodies as an indicator of pharmacokinetics.


Asunto(s)
Anticuerpos , Proteínas , Electricidad Estática , Proteínas/química , Solubilidad , Viscosidad
12.
Cogn Emot ; 37(7): 1161-1166, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37990888

RESUMEN

This editorial introduces an invited article by Andreas Eder on a new perceptual control theory of action choice, based on the comparison of real and simulated interoceptive signals generated by action alternatives. Eder extends the cognitive action-control framework, postulating a bi-directional connection between outcomes and actions by introducing "emotional feelings", defined as valued interoceptive signals from the body. An invited commentary by Agnes Moors compares this theory with her own goal-directed theory of action control. While agreeing on the central role of a control cycle and the goal-directed nature of emotional actions, Moors disagrees on the content of the representations involved in the control cycle and the nature of the feelings involved. A second commentary by Bob Bramson and Karin Roelofs discusses the issues of the distinction between perception control vs. action control, the need for biologically plausible implementation alternatives, and potential implications for psychopathology and clinical intervention. Finally, the potential relevance of predictive coding theory and the role of appraisal processes in emotion generation with respect to their bearing on action comparison and choice are discussed.


Asunto(s)
Conducta de Elección , Emociones , Humanos
13.
Antibodies (Basel) ; 12(4)2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37873864

RESUMEN

Antibodies and other new antibody-like formats have emerged as one of the most rapidly growing classes of biotherapeutic proteins. Understanding the structural features that drive antibody function and, consequently, their molecular recognition is critical for engineering antibodies. Here, we present the structural architecture of conventional IgG antibodies alongside other formats. We emphasize the importance of considering antibodies as conformational ensembles in solution instead of focusing on single-static structures because their functions and properties are strongly governed by their dynamic nature. Thus, in this review, we provide an overview of the unique structural and dynamic characteristics of antibodies with respect to their antigen recognition, biophysical properties, and effector functions. We highlight the numerous technical advances in antibody structure prediction and design, enabled by the vast number of experimentally determined high-quality structures recorded with cryo-EM, NMR, and X-ray crystallography. Lastly, we assess antibody and vaccine design strategies in the context of structure and dynamics.

14.
bioRxiv ; 2023 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-37790368

RESUMEN

Voltage-dependent and Ca2+-dependent inactivation (VDI and CDI, respectively) of CaV channels are two biologically consequential feedback mechanisms that fine-tune Ca2+ entry into neurons and cardiomyocytes. Although known to be initiated by distinct molecular events, how these processes obstruct conduction through the channel pore remains poorly defined. Here, focusing on ultra-highly conserved tryptophan residues in the inter-domain interfaces near the selectivity filter of CaV1.3, we demonstrate a critical role for asymmetric conformational changes in mediating VDI and CDI. Specifically, mutagenesis of the domain III-IV interface, but not others, enhanced VDI. Molecular dynamics simulations demonstrate that mutations in distinct selectivity filter interfaces differentially impact conformational flexibility. Furthermore, mutations in distinct domains preferentially disrupt CDI mediated by the N- versus C-lobes of CaM, thus uncovering a scheme of structural bifurcation of CaM signaling. These findings highlight the fundamental importance of the asymmetric arrangement of the pseudo-tetrameric CaV pore domain for feedback inhibition.

15.
Expert Rev Gastroenterol Hepatol ; 17(8): 753-767, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37480322

RESUMEN

INTRODUCTION: Most guidelines for IBD still recommend step-by-step therapy with initially classic drugs such aminosalicylates (in ulcerative colitis) or steroids but avoid prioritizing certain biological drugs and JAK inhibitors in the complicated course. This review provides an aid to pending therapy decisions. AREAS COVERED: In this review, we analyze the evidence for Crohn's disease as well as ulcerative colitis in order to optimize and 'personalize' the choice of therapy, especially in difficult cases. The relevant publications in Pubmed were identified in a continuous literature review with the key words 'Crohn´s disease' and 'ulcerative colitis.' EXPERT OPINION: Based on this complex data set following standard therapies steroid-refractory Crohn´s disease should preferentially be treated with combined infliximab plus azathioprine or risankizumab, in second line after their failure with ustekinumab or 7adalimumab. In steroid-refractory ulcerative colitis infliximab plus azathioprine or upadacitinib should be preferred in first line, filgotinib, tofacitinib or ustekinumab in second line. A steroid-dependent course in both diseases requires azathioprine or vedolizumab, in second line infliximab or Janus kinase inhibitors. The conclusions drawn from these complex data may be helpful for individual decision making in daily clinical practice.


Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Inhibidores de las Cinasas Janus , Humanos , Azatioprina/uso terapéutico , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/tratamiento farmacológico , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/tratamiento farmacológico , Infliximab/uso terapéutico , Ustekinumab/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Esteroides/uso terapéutico , Inhibidores de las Cinasas Janus/uso terapéutico
16.
J Breath Res ; 17(4)2023 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-37406623

RESUMEN

The use of volatile biomarkers in exhaled breath as predictors to individual drug response would advance the field of personalised medicine by providing direct information on enzyme activity. This would result in enormous benefits, both for patients and for the healthcare sector. Non-invasive breath tests would also gain a high acceptance by patients. Towards this goal, differences in metabolism resulting from extensive polymorphisms in a major group of drug-metabolizing enzymes, the cytochrome P450 (CYP) family, need to be determined and quantified. CYP2C9 is responsible for metabolising many crucial drugs (e.g., diclofenac) and food ingredients (e.g., limonene). In this paper, we provide a proof-of-concept study that illustrates thein vitrobioconversion of diclofenac in recombinant HEK293T cells overexpressing CYP2C9 to 4'-hydroxydiclofenac. Thisin vitroapproach is a necessary and important first step in the development of breath tests to determine and monitor metabolic processes in the human body. By focusing on the metabolic conversion of diclofenac, we have been able to establish a workflow using a cell-based system for CYP2C9 activity. Furthermore, we illustrate how the bioconversion of diclofenac is limited in the presence of limonene, which is another CYP2C9 metabolising substrate. We show that increasing limonene levels continuously reduce the production of 4'-hydroxydiclofenac. Michaelis-Menten kinetics were performed for the diclofenac 4'-hydroxylation with and without limonene, giving a kinetic constant of the reaction,KM, of 103µM and 94.1µM, respectively, and a maximum reaction rate,Vmax, of 46.8 pmol min-1106cells-1and 56.0 pmol min-1106cells-1with and without the inhibitor, respectively, suggesting a non-competitive or mixed inhibition type. The half-maximal inhibitory concentration value (IC50) for the inhibition of the formation of 4'-hydroxydiclofenace by limonene is determined to be 1413µM.


Asunto(s)
Hidrocarburo de Aril Hidroxilasas , Diclofenaco , Humanos , Diclofenaco/metabolismo , Diclofenaco/farmacología , Citocromo P-450 CYP2C9/genética , Citocromo P-450 CYP2C9/metabolismo , Hidrocarburo de Aril Hidroxilasas/metabolismo , Células HEK293 , Limoneno , Medicina de Precisión , Flujo de Trabajo , Pruebas Respiratorias , Sistema Enzimático del Citocromo P-450/metabolismo
17.
Proteins ; 91(9): 1316-1328, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37376973

RESUMEN

In the last years, antibodies have emerged as a promising new class of therapeutics, due to their combination of high specificity with long serum half-life and low risk of side-effects. Diabodies are a popular novel antibody format, consisting of two Fv domains connected with short linkers. Like IgG antibodies, they simultaneously bind two target proteins. However, they offer altered properties, given their smaller size and higher rigidity. In this study, we conducted the-to our knowledge-first molecular dynamics (MD) simulations of diabodies and find a surprisingly high conformational flexibility in the relative orientation of the two Fv domains. We observe rigidifying effects through the introduction of disulfide bonds in the Fv -Fv interface and characterize the effect of different disulfide bond locations on the conformation. Additionally, we compare VH -VL orientations and paratope dynamics between diabodies and an antigen binding fragment (Fab) of the same sequence. We find mostly consistent structures and dynamics, indicating similar antigen binding properties. The most significant differences can be found within the CDR-H2 loop dynamics. Of all CDR loops, the CDR-H2 is located closest to the artificial Fv -Fv interface. All examined diabodies show similar VH -VL orientations, Fv -Fv packing and CDR loop conformations. However, the variant with a P14C-K64C disulfide bond differs most from the Fab in our measures, including the CDR-H3 loop conformational ensemble. This suggests altered antigen binding properties and underlines the need for careful validation of the disulfide bond locations in diabodies.


Asunto(s)
Anticuerpos , Fragmentos Fab de Inmunoglobulinas , Conformación Proteica , Sitios de Unión de Anticuerpos , Fragmentos Fab de Inmunoglobulinas/química , Disulfuros
18.
Cells ; 12(9)2023 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-37174665

RESUMEN

The proto-oncogene myc has been intensively studied primarily in vertebrate cell culture systems. Myc transcription factors control fundamental cellular processes such as cell proliferation, cell cycle control and stem cell maintenance. Myc interacts with the Max protein and Myc/Max heterodimers regulate thousands of target genes. The genome of the freshwater polyp Hydra encodes four myc genes (myc1-4). Previous structural and biochemical characterization showed that the Hydra Myc1 and Myc2 proteins share high similarities with vertebrate c-Myc, and their expression patterns suggested a function in adult stem cell maintenance. In contrast, an additional Hydra Myc protein termed Myc3 is highly divergent, lacking the common N-terminal domain and all conserved Myc-boxes. Single cell transcriptome analysis revealed that the myc3 gene is expressed in a distinct population of interstitial precursor cells committed to nerve- and gland-cell differentiation, where the Myc3 protein may counteract the stemness actions of Myc1 and Myc2 and thereby allow the implementation of a differentiation program. In vitro DNA binding studies showed that Myc3 dimerizes with Hydra Max, and this dimer efficiently binds to DNA containing the canonical Myc consensus motif (E-box). In vivo cell transformation assays in avian fibroblast cultures further revealed an unexpected high potential for oncogenic transformation in the conserved Myc3 C-terminus, as compared to Hydra Myc2 or Myc1. Structure modeling of the Myc3 protein predicted conserved amino acid residues in its bHLH-LZ domain engaged in Myc3/Max dimerization. Mutating these amino acid residues in the human c-Myc (MYC) sequence resulted in a significant decrease in its cell transformation potential. We discuss our findings in the context of oncogenic transformation and cell differentiation, both relevant for human cancer, where Myc represents a major driver.


Asunto(s)
Hydra , Animales , Humanos , Hydra/genética , Secuencia de Aminoácidos , Genes myc , Secuencias Hélice-Asa-Hélice , Aminoácidos
19.
Nat Commun ; 14(1): 2815, 2023 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-37198165

RESUMEN

A primary objective in malaria vaccine design is the generation of high-quality antibody responses against the circumsporozoite protein of the malaria parasite, Plasmodium falciparum (PfCSP). To enable rational antigen design, we solved a cryo-EM structure of the highly potent anti-PfCSP antibody L9 in complex with recombinant PfCSP. We found that L9 Fab binds multivalently to the minor (NPNV) repeat domain, which is stabilized by a unique set of affinity-matured homotypic, antibody-antibody contacts. Molecular dynamics simulations revealed a critical role of the L9 light chain in integrity of the homotypic interface, which likely impacts PfCSP affinity and protective efficacy. These findings reveal the molecular mechanism of the unique NPNV selectivity of L9 and emphasize the importance of anti-homotypic affinity maturation in protective immunity against P. falciparum.


Asunto(s)
Vacunas contra la Malaria , Malaria Falciparum , Malaria , Humanos , Epítopos , Proteínas Protozoarias/química , Malaria/prevención & control , Malaria Falciparum/prevención & control , Plasmodium falciparum , Anticuerpos Antiprotozoarios
20.
Chemphyschem ; 24(15): e202300262, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37199236

RESUMEN

We present infrared predissociation spectra of C2 N- (H2 ) and C 3 N- (H2 ) in the 300-1850 cm-1 range. Measurements were performed using the FELion cryogenic ion trap end user station at the Free Electron Lasers for Infrared eXperiments (FELIX) laboratory. For C2 N- (H2 ), we detected the CCN bending and CC-N stretching vibrations. For the C3 N- (H2 ) system, we detected the CCN bending, the CC-CN stretching, and multiple overtones and/or combination bands. The assignment and interpretation of the presented experimental spectra is validated by calculations of anharmonic spectra within the vibrational configuration interaction (VCI) approach, based on potential energy surfaces calculated at explicitly correlated coupled cluster theory (CCSD(T)-F12/cc-pVTZ-F12). The H2 tag acts as an innocent spectator, not significantly affecting the C2,3 N- bending and stretching mode positions. The recorded infrared predissociation spectra can thus be used as a proxy for the vibrational spectra of the bare anions.

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