Search results for "IIN"
showing 10 items of 1385 documents
Inverse Conformational Selection in Lipid–Protein Binding
2021
International audience; Interest in lipid interactions with proteins and other biomolecules is emerging not only in fundamental biochemistry but also in the field of nanobiotechnology where lipids are commonly used, for example, in carriers of mRNA vaccines. The outward-facing components of cellular membranes and lipid nanoparticles, the lipid headgroups, regulate membrane interactions with approaching substances, such as proteins, drugs, RNA, or viruses. Because lipid headgroup conformational ensembles have not been experimentally determined in physiologically relevant conditions, an essential question about their interactions with other biomolecules remains unanswered: Do headgroups excha…
Structure of SNX9 SH3 in complex with a viral ligand reveals the molecular basis of its unique specificity for alanine-containing class I SH3 motifs
2021
Class I SH3 domain-binding motifs generally comply with the consensus sequence [R/K]x0PxxP, the hydrophobic residue 0 being proline or leucine. We have studied the unusual 0 = Ala-specificity of SNX9 SH3 by determining its complex structure with a peptide present in eastern equine encephalitis virus (EEEV) nsP3. The structure revealed the length and composition of the n-Src loop as important factors determining specificity. We also compared the affinities of EEEV nsP3 peptide, its mutants, and cellular ligands to SNX9 SH3. These data suggest that nsP3 has evolved to minimize reduction of conformational entropy upon binding, hence acquiring stronger affinity, enabling takeover of SNX9. The R…
The primary structural photoresponse of phytochrome proteins captured by a femtosecond X-ray laser
2019
Phytochrome proteins control the growth, reproduction, and photosynthesis of plants, fungi, and bacteria. Light is detected by a bilin cofactor, but it remains elusive how this leads to activation of the protein through structural changes. We present serial femtosecond X-ray crystallographic data of the chromophore-binding domains of a bacterial phytochrome at delay times of 1 ps and 10 ps after photoexcitation. The data reveal a twist of the D-ring, which leads to partial detachment of the chromophore from the protein. Unexpectedly, the conserved so-called pyrrole water is photodissociated from the chromophore, concomitant with movement of the A-ring and a key signaling aspartate. The chan…
A spontaneous mitonuclear epistasis converging on Rieske Fe-S protein exacerbates complex III deficiency in mice
2020
We previously observed an unexpected fivefold (35 vs. 200 days) difference in the survival of respiratory chain complex III (CIII) deficient Bcs1lp.S78G mice between two congenic backgrounds. Here, we identify a spontaneous homoplasmic mtDNA variant (m.G14904A, mt-Cybp.D254N), affecting the CIII subunit cytochrome b (MT-CYB), in the background with short survival. We utilize maternal inheritance of mtDNA to confirm this as the causative variant and show that it further decreases the low CIII activity in Bcs1lp.S78G tissues to below survival threshold by 35 days of age. Molecular dynamics simulations predict D254N to restrict the flexibility of MT-CYB ef loop, potentially affecting RISP dyna…
UV-Vis Spectroscopy Reveals a Correlation Between Y263 and BV Protonation States in Bacteriophytochromes
2019
Red‐light photosensory proteins, phytochromes, link light activation to biological functions by interconverting between two conformational states. For this, they undergo large‐scale secondary and tertiary changes which follow small‐scale Z to E bond photoisomerization of the covalently bound bilin chromophore. The complex network of amino acid interactions in the chromophore‐binding pocket plays a central role in this process. Highly conserved Y263 and H290 have been found to be important for the photoconversion yield, while H260 has been identified as important for bilin protonation and proton transfer steps. Here, we focus on the roles these amino acids are playing in preserving the chemi…
Teacher ability evaluation and changes in elementary student profiles of motivation and performance in mathematics
2018
Abstract The aim of this person-centered study is to identify the profiles of interest value, self-concept, and performance in the domain of mathematics among elementary school students and to examine the stability and changes in these profiles from grade 1 to grade 2. Teacher-reported evaluations of students' mathematical ability and gender were examined as predictors of changes in the student profiles. The sample consisted of 237 students (46.8% girls). The latent profile analysis identified four profiles: 1) low levels of interest value, medium levels of self-concept and performance; 2) low levels of interest value, self-concept and performance; 3) high levels of interest value, self-con…
Eficacia analgésica del diclofenaco sódico vs. ibuprofeno después de la extracción quirúrgica de un tercer molar inferior incluido
2004
-Objetivo: En este estudio evaluamos la eficacia analgésica del diclofenaco sódico en comparación con el ibuprofeno, después de la extracción quirúrgica de un tercer molar inferior incluido. -Diseño de estudio: Los pacientes que participaron en el estudio fueron distribuidos de forma aleatoria en dos grupos. Uno fue el grupo ibuprofeno y el otro el grupo diclofenaco. La intervención practicada fue la extracción quirúrgica de un tercer molar inferior cuya dificultad fue determinada en función del grado de inclusión en todos los pacientes. Las variables registradas fueron la intensidad del dolor y la necesidad de medicación de rescate durante un periodo de una semana. Los registros se realiza…
A Decomposition Theorem for the Fuzzy Henstock Integral
2012
We study the fuzzy Henstock and the fuzzy McShane integrals for fuzzy-number valued functions. The main purpose of this paper is to establish the following decomposition theorem: a fuzzy-number valued function is fuzzy Henstock integrable if and only if it can be represented as a sum of a fuzzy McShane integrable fuzzy-number valued function and of a fuzzy Henstock integrable fuzzy number valued function generated by a Henstock integrable function.
Measuring Public Speaking Anxiety: Self-report, behavioral, and physiological
2021
Self-reports are typically used to assess public speaking anxiety. In this study, we examined whether self-report, observer report, and behavioral and physiological reactivity were associated with each other during a speech challenge task. A total of 95 university students completed a self-report measure of public speaking anxiety before and after the speech challenge. Speech duration (i.e., behavioral measure), physiological reactivity, as well as speech performance evaluated by the participants and observers were also recorded. The results suggest that self-reported public speaking anxiety predicts speech duration, as well as speech quality, as rated by the participants themselves and ob…
An attempt to enhance neurogenesis of mdx mice via aerobic exercise and myostatin inhibition
2013
Duchennen lihasdystrofia (DMD) on perinnöllinen sairaus, jonka esiintyvyys on noin 1/3600 poikavauvasta. Siihen liittyy lihasten heikkoutta, rappeutumista ja kognitiivista vajavaisuutta. Taudin aiheuttaa mutatoitunut geeni dystrophiini proteiinille. On esitetty, että kognitiivinen vajavaisuus johtuu taudin vaikutuksesta ehkäistä neurogeneesiä. Neurogeneesi on prosessi, joka jatkuvasti synnyttää uusia hermosoluja pääasiallisesti subventikulaari alueella ja hippokampuksen dentate gyruksella. Hoitoa ja parannusta tautiin tutkitaan yleensä mdx-hiirillä, joiden taudin etiologia on riittävän lähellä ihmisten tautia. Tämä tutkimus keskittyy pyrkimykseen vaikuttaa mdx-hiirten neurogeneesiin aerobis…