Mechanism of Peroxynitrite Interaction with Ferric Nitrobindin: A Computational Study.

Nitrobindins (Nbs) are all-β-barrel heme proteins present along the evolutionary ladder. They display a highly solvent-exposed ferric heme group with the iron atom being coordinated by the proximal His residue and a water molecule at the distal position. Ferric nitrobindins (Nb(III)) play a role in the conversion of toxic peroxynitrite (ONOO) to harmless nitrate, with the value of the second-order rate constant being similar to those of most heme proteins.

Variety is the spice: The role of morphological variation of Triatoma infestans (Hemiptera, Reduviidae) at a macro-scale.

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi (Chagas, 1909). One of the primary vectors of T. cruzi in South America is Triatoma infestans (Klug, 1834).

Assessment of Embedding Schemes in a Hybrid Machine Learning/Classical Potentials (ML/MM) Approach.

Machine learning (ML) methods have reached high accuracy levels for the prediction of in vacuo molecular properties. However, the simulation of large systems solely through ML methods (such as those based on neural network potentials) is still a challenge. In this context, one of the most promising frameworks for integrating ML schemes in the simulation of complex molecular systems are the so-called ML/MM methods.

Gaming expertise induces meso‑scale brain plasticity and efficiency mechanisms as revealed by whole-brain modeling.

Video games are a valuable tool for studying the effects of training and neural plasticity on the brain. However, the underlying mechanisms related to plasticity-associated brain structural changes and their impact on brain dynamics are unknown. Here, we used a semi-empirical whole-brain model to study structural neural plasticity mechanisms linked to video game expertise.

Proximal ligand tunes active site structure and reactivity in bacterial L. monocytogenes coproheme ferrochelatase.

Ferrochelatases catalyze the insertion of ferrous iron into the porphyrin during the heme b biosynthesis pathway, which is fundamental for both prokaryotes and eukaryotes. Interestingly, in the active site of ferrochelatases, the proximal ligand coordinating the porphyrin iron of the product is not conserved, and its catalytic role is still unclear. Here we compare the L.

Amphiphilic Low-Molecular-Weight Gelators Bearing β---Acetylglucosamine Linked to a Tartaric Acid Scaffold: Synthesis, Self-Assembly and Wheat Germ Agglutinin Binding.

The self-assembly of carbohydrate-based amphiphiles can lead to colloidal soft materials such as supramolecular gels featuring highly desirable characteristics like biodegradability and biocompatibility. The report herein presents the synthesis, characterization and supramolecular self-assembly, physical gelation and wheat lectin binding of two structurally related amphiphilic compounds having β---acetylglucosamine residues linked to a 2,3-diacyl-,'-dipropargylated-l-tartaric diamide. A 1-thio-β--acetyl-d-glucosamine precursor attached to a conveniently functionalized linker with an azido group was synthesized by means of a one-pot procedure followed by deprotection.

Gaming expertise induces meso-scale brain plasticity and efficiency mechanisms as revealed by whole-brain modeling Gaming expertise, neuroplasticity and functional dynamics.

Video games are a valuable tool for studying the effects of training and neural plasticity on the brain. However, the underlaying mechanisms related to plasticity-induced brain structural changes and their impact in brain dynamics are unknown. Here, we used a semi-empirical whole-brain model to study structural neural plasticity mechanisms linked to video game expertise.

Population structure and migration in Triatoma infestans (Hemiptera: Reduviidae) from the Argentine Chaco: An integration of genetic and morphometric data.

Genetic and morphological structure of vector populations are useful to identify panmictic groups, reinfestation sources and minimal units for control interventions. Currently, no studies have integrated genetic and morphometric data in Triatoma infestans (Hemiptera: Reduviidae), one of the main vectors of Trypanosoma cruzi. We characterized the genetic and phenotypic structure of T.

Nitric oxide binding to ferrous nitrobindins: A computer simulation investigation.

Nitrobindins (Nbs) represent an evolutionary conserved all-β-barrel heme-proteins displaying a highly solvent-exposed heme-Fe(III) atom, coordinated by a proximal His residue. Interestingly, even if the distal side is exposed to the solvent, the value of the second order rate constants for ligand binding to the ferrous derivative is almost one order of magnitude lower than those reported for myoglobins (Mbs). Noteworthy, nitric oxide binding to the sixth coordination position of the heme-Fe(II)-atom causes the cleavage or the severe weakening of the proximal His-Fe(II) bond.

Low-dimensional organization of global brain states of reduced consciousness.

Brain states are frequently represented using a unidimensional scale measuring the richness of subjective experience (level of consciousness). This description assumes a mapping between the high-dimensional space of whole-brain configurations and the trajectories of brain states associated with changes in consciousness, yet this mapping and its properties remain unclear. We combine whole-brain modeling, data augmentation, and deep learning for dimensionality reduction to determine a mapping representing states of consciousness in a low-dimensional space, where distances parallel similarities between states.

Biophysical evaluation of the oligomerization and conformational properties of the N-terminal domain of TDP-43.

TDP-43 is an RNA-binding protein that presents four domains comprising an N-terminal region, two RNA recognition motifs and a C-terminal region. The N-terminal domain (NTD) has a relevant role in the oligomerization and splicing activity of TDP-43. In this work, we have expressed, purified and biophysically characterized the region that includes residues 1 to 102 that contains the nuclear localization signal (residues 80-102, NLS).

Novel Lennard-Jones Parameters for Cysteine and Selenocysteine in the AMBER Force Field.

Cysteine is a common amino acid with a thiol group that plays a pivotal role in a variety of scenarios in redox biochemistry. In contrast, selenocysteine, the 21st amino acid, is only present in 25 human proteins. Classical force-field parameters for cysteine and selenocysteine are still scarce.

Phenotypic variability in traits related to flight dispersal in the wing dimorphic species Triatoma guasayana.

Background: Triatoma guasayana is considered an emerging vector of Chagas disease in the Southern Cone of South America. The presence of a triatomine population with brachypterous individuals, in which both wings are reduced, has recently been reported for this species. The aim of the present study was to determine if flight-related traits varied across populations, if these traits could explain differences in flight capacity across populations and if flight-related traits are associated with geographic and/or climatic variation.

An ecomorphological approach to the relationship between craniomandibular morphology and diet in sigmodontine rodents from central-eastern Argentina.

The key role of the skull in food intake and processing implicates its morphology should be to some extent adapted to the functional demands present in different diets, while also showing similarities between those which are closely related. Sigmodontine rodents, with a generalist body plan and broad dietary habits, are an interesting case study to explore these relationships. We used linear morphometrics to assess craniomandibular morphology, and explored its relationship with dietary composition and phylogeny in a sample of sigmodontines from central-eastern Argentina, representative of this subfamily's morphological and ecological diversity.

Dopamine activates astrocytes in prefrontal cortex via α1-adrenergic receptors.

The prefrontal cortex (PFC) is a hub for cognitive control, and dopamine profoundly influences its functions. In other brain regions, astrocytes sense diverse neurotransmitters and neuromodulators and, in turn, orchestrate regulation of neuroactive substances. However, basic physiology of PFC astrocytes, including which neuromodulatory signals they respond to and how they contribute to PFC function, is unclear.

Synthesis, structural and electrochemical properties of a new family of amino-acid-based coordination complexes.

Metalloproteins involved in oxidation-reduction processes in metabolism are fundamental for the wellbeing of every organism. The use of amino-acid-based compounds as ligands for the construction of biomimetic coordination systems represents a promising alternative for the development of new catalysts. Herein is presented a new family of copper, zinc and nickel coordination compounds, which show four-, five- and six- coordination geometries, synthesized using Schiff base ligands obtained from the amino acids L-alanine and L-phenylalanine.

Atomistic insight into the essential binding event of ACE2-derived peptides to the SARS-CoV-2 spike protein.

The pathogenic agent of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters into human cells through the interaction between the receptor binding domain (RBD) of its spike glycoprotein and the angiotensin-converting enzyme 2 (ACE2) receptor. Efforts have been made towards finding antivirals that block this interaction, therefore preventing infection. Here, we determined the binding affinity of ACE2-derived peptides to the RBD of SARS-CoV-2 experimentally and performed MD simulations in order to understand key characteristics of their interaction.

Low genetic variation of foliar traits among Prosopis chilensis (Leguminosae) provenances.

Prosopis chilensis (Molina) Stuntz (Leguminosae) is a valuable native species in Argentina that has been proposed to be used in reforestation, afforestation and restoration programmes. Natural provenances show important differentiation in height, shape, spine size, fruits and foliar traits throughout their distribution in the semiarid Monte ecoregion. The goal of this work was to characterize the genetic basis of the leaf variation in P.

Over-dispersed Trypanosoma cruzi parasite load in sylvatic and domestic mammals and humans from northeastern Argentina.

Background: The distribution of parasite load across hosts may modify the transmission dynamics of infectious diseases. Chagas disease is caused by a multi-host protozoan, Trypanosoma cruzi, but the association between host parasitemia and infectiousness to the vector has not been studied in sylvatic mammalian hosts. We quantified T.

In Sickness and in Health: Narratives on Epidemics as Tools for Science Teaching in Secondary Schools.

In the context of the current COVID-19 pandemic, we deem of importance the identification of what content is privileged in secondary schools around health and disease. From our point of view, a relevant task is to accompany science teachers in their transit from teaching information to be evoked to teaching knowledge on that content that enables students' action. Accordingly, our aims in this article are (a) to move away from the extended biomedical approach to teaching topics around public health which some authors consider reductive and (b) to explore instead a multi-causal and multi-referential approach, conveyed through narratives.

Efficient decolorization of recalcitrant dyes at neutral/alkaline pH by a new bacterial laccase-mediator system.

Laccases and laccase-mediator systems (LMS) are versatile catalysts that can oxidize a broad range of substrates coupled to the sole reduction of dioxygen to water. They possess many biotechnological applications in paper, textile, and food industries, bioethanol production, organic synthesis, detection and degradation of pollutants, and biofuel cell development. In particular, bacterial laccases are getting relevance due to their activity in a wide range of pH and temperature and their robustness under harsh conditions.

Perigestational alcohol consumption induces altered early placentation and organogenic embryo growth restriction by disruption of trophoblast angiogenic factors.

Research Question: Maternal alcohol consumption produces fetal retardation and malformations, probably associated with placental defects. Does perigestational alcohol consumption up to organogenesis lead to abnormal placentation and embryo growth restriction by disrupting the vascular endothelial growth factor (VEGF) system in embryo-placental development?

Design: Female mice were treated with 10% ethanol in drinking water before and up to day 10 of gestation. Control mice received ethanol-free water.

The impact of livestock grazing on the evapotranspiration-vegetation biomass relationship in a Southern Hemisphere salt marsh, Buenos Aires (Argentina).

Among the ecosystem services provided by salt marshes is the use of their natural vegetation as pastures for livestock production. As a result, the prediction of biomass productivity can be of great interest for the sustainable management of these environments. Evapotranspiration is one of the variables most used to estimate the yield of green biomass in pastures and crops, which to date has not been examined for natural environments such as salt marshes.

Diagnose of Indigenous Arbuscular Mycorrhizal Communities Associated to Cynara cardunculus L. var. altilis and var. sylvestris.

Cynara cardunculus L. is a perennial species with high potential for bioenergy production. Arbuscular mycorrhizal symbiosis (AMF) is probably the terrestrial symbiosis most extended on earth.