Search results for "proteiinit"
showing 10 items of 164 documents
Predictive value of p53, Ki67 and TLR5 in neoplastic progression of Barrett’s esophagus: a matched case–control study
2022
Abstract Barrett’s esophagus progresses to high-grade dysplasia or cancer along the well-established metaplasia-dysplasia-adenocarcinoma sequence. The aim of this study was to evaluate the value of p53, Ki67, and toll-like receptor 5 (TLR5) in prediction of malignant progression of Barrett’s metaplasia and low-grade dysplasia. This was a retrospective matched case–control study based on Northern and Central Finland population. Patients diagnosed with esophageal high-grade dysplasia or adenocarcinoma were included. From these patients, all previous endoscopy samples were obtained along with original diagnostic HE-slides and clinical data. Age- and sex-matched patients with non-progressing Ba…
Proteiinilisän vaikutus teholajien urheilijoiden suorituskykyyn ja palautumiseen 12 vuorokauden intensiivisellä harjoittelujaksolla
2012
Jaakko Tornberg, 2012. Proteiinilisän vaikutus teholajien urheilijoiden suorituskykyyn ja palautumiseen 12 vuorokauden intensiivisellä harjoittelujaksolla. Valmennus- ja testausopin pro gradu -tutkielma. Jyväskylän yliopisto, liikuntabiologian laitos. 99s. Urheilijoiden optimaalisen proteiininsaannin määristä, proteiinien laadusta ja nauttimisen ajoituksesta harjoittelussa on tieteellisessä kirjallisuudessa erilaisia näkemyksiä. Tämän tutkimuksen tarkoituksena oli tutkia neljä kertaa vuorokaudessa nautittavan proteiiniravintolisän (kaksinkertaistaa proteiininsaannin vuorokausimäärän) vaikutusta teholajien urheilijoiden suorituskykyyn ja palautumiseen intensiivisellä 12 vuorokauden harjoitte…
Observe while it happens : catching photoactive proteins in the act with non-adiabatic molecular dynamics simulations
2020
Organisms use photo-receptors to react to light. The first step is usually the absorption of a photon by a prosthetic group embedded inside the photo-receptor, often a conjugated chromophore. The electronic changes in the chromophore induced by photo-absorption can trigger a cascade of structural or chemical transformations that culminate into a response to light. Understanding how these proteins have evolved to mediate their activation process has remained challenging because the required time and spacial resolutions are notoriously difficult to achieve experimentally. Therefore, mechanistic insights into photoreceptor activation have been predominantly obtained with computer simulations. …
Protonation of the Biliverdin IXα Chromophore in the Red and Far-Red Photoactive States of Bacteriophytochrome
2019
The tetrapyrrole chromophore biliverdin IXα (BV) in the bacteriophytochrome from Deinococcus radiodurans (DrBphP) is usually assumed to be fully protonated, but this assumption has not been systematically validated by experiments or extensive computations. Here, we use force field molecular dynamics simulations and quantum mechanics/molecular mechanics calculations with density functional theory and XMCQDPT2 methods to investigate the effect of the five most probable protonation forms of BV on structural stability, binding pocket interactions, and absorption spectra in the two photochromic states of DrBphP. While agreement with X-ray structural data and measured UV/vis spectra suggest that …
Red Light Optogenetics in Neuroscience
2022
Optogenetics, a field concentrating on controlling cellular functions by means of light-activated proteins, has shown tremendous potential in neuroscience. It possesses superior spatiotemporal resolution compared to the surgical, electrical, and pharmacological methods traditionally used in studying brain function. A multitude of optogenetic tools for neuroscience have been created that, for example, enable the control of action potential generation via light-activated ion channels. Other optogenetic proteins have been used in the brain, for example, to control long-term potentiation or to ablate specific subtypes of neurons. In in vivo applications, however, the majority of optogenetic too…
The Interconnecting Hairpin Extension "Arm": An Essential Allosteric Element of Phytochrome Activity
2023
In red-light sensing phytochromes, isomerization of the bilin chromophore triggers structural and dynamic changes across multiple domains, ultimately leading to control of the output module (OPM) activity. In between, a hairpin structure, "arm", extends from an interconnecting domain to the chromophore region. Here, by removing this protein segment in a bacteriophytochrome from Deinococcus radiodurans (DrBphP), we show that the arm is crucial for signal transduction. Crystallographic, spectroscopic, and biochemical data indicate that this variant maintains the properties of DrBphP in the resting state. Spectroscopic data also reveal that the armless systems maintain the ability to respond t…
Predictive First-principles Modeling of a Photosynthetic Antenna Protein : The Fenna-Matthews-Olson Complex
2020
High efficiency of light harvesting in photosynthetic pigment-protein complexes is governed by evolutionary-perfected protein-assisted tuning of individual pigment properties and inter-pigment interactions. Due to the large number of spectrally overlapping pigments in a typical photosynthetic complex, experimental methods often fail to unambiguously identify individual chromophore properties. Here we report a first principles-based modeling protocol capable of predicting properties of pigments in protein environment to a high precision. The technique was applied to successfully uncover electronic properties of the Fenna-Matthews-Olson (FMO) pigment-protein complex. Each of the three subunit…
Protein recovery as a resource from waste specifically via membrane technology : from waste to wonder
2021
Economic growth and the rapid increase in the world population has led to a greater need for natural resources, which in turn, has put pressure on said resources along with the environment. Water, food, and energy, among other resources, pose a huge challenge. Numerous essential resources, including organic substances and valuable nutrients, can be found in wastewater, and these could be recovered with efficient technologies. Protein recovery from waste streams can provide an alternative resource that could be utilized as animal feed. Membrane separation, adsorption, and microbe-assisted protein recovery have been proposed as technologies that could be used for the aforementioned protein re…
Kasviksiin pohjautuvan ruokavalion vaikutus elimistön proteiiniaineenvaihduntaan kuntoilijoilla
2014
Nykyään moni valitsee kasvisruokavalion terveydellisin ja ekologisin perustein. Erityisesti punaisen lihan mahdolliset haittavaikutukset ovat saaneet monet jättämään punaisen lihan pois ruokavaliostaan ja lisää-mään kasvisten syöntiä. Tällöin voidaan puhua kasvispainotteisesta tai semivegetaarisesta ruokavaliosta, koska ruokavalio sisältää satunnaisesti vaaleaa lihaa sekä kalaa. Tämän tutkimuksen tarkoituksena oli selvittää, miten kasviksiin pohjautuva ruokavalio vaikuttaa elimistön proteiiniaineenvaihduntaan. Tavoit-teena oli, että tulosten perusteella voitaisiin arvioida erityisesti sitä, onko kasviksiin pohjautuvasta ruoka-valiosta saadulla proteiinilla erilaisia vaikutuksia elimistön pr…
Proteiiniaineenvaihdunta ja sen tutkiminen isotooppi-infuusio -menetelmällä
2001
Tarja Nykänen, 2001. Proteiiniaineenvaihdunta ja sen tutkiminen isotooppi-infuusio - menetelmällä. Liikuntafysiologian pro gradu -tutkielma. Jyväskylän yliopisto, liikuntabiologian laitos. 74s. Tämän työn tarkoituksena oli tutkia proteiiniaineenvaihdunnan tutkimuksessa käytettävän isotooppi-infuusio -menetelmän toistettavuutta ja tarkkuutta sekä osoittaa sitä käyttäen maksimivoimaharjoituksen aiheuttavan muutoksen proteiiniaineenvaihdunnan muuttujissa. Menetelmä perustuu kolmiallasmalliin, 'joka kuvaa aminohappojen liikettä kolmen eri aminohappoaltaan; valtimon, laskimon ja lihaksen välillä. Menetelmässä koehenkilöön infusoidaan suonensisäisesti isotoopilla leimattua aminohappoa. Lepomittau…