Search results for "RGD"
showing 10 items of 81 documents
Baktērijas Borrelia burgdorferi proteīna BBP28 strukturālie pētījumi
2017
Laima slimība ir visizplatītākā ar vektoriem pārnēsātā slimība Amerikas Savienotajās Valstīs. Neraugoties uz tās plašo izplatību un smagajiem slimības simptomiem, pret to vēl aizvien nav pieejama vakcīna. Darba mērķis bija ekspresēt Laima slimības izraisītājas, baktērijas (Borrelia burgdorferi), ar membrānu saistīto lipoproteīnu BBP28 un noteikt tā struktūru. Izmantojot KMR datus, tika aprēķinātas divas BBP28 proteīna struktūras - viena pilna garuma un otra saīsinātai proteīna sekvencei, kas nesatur nestrukturēto 27 aa garo N gala segmentu. Strukturēto BBP28 daļu veido piecas α-spirāles un 14 aa gara virkne C-galā, kas kovalenti piesaistīta ar disulfīda saiti pie 4. un 5. α-spirāli savienoj…
Tick-borne pathogens in Ixodes ricinus ticks collected from migratory birds in southern Norway
2020
Birds are important hosts for the first life stages of the Ixodes ricinus tick and they can transport their parasites over long distances. The aim of this study was to investigate the prevalence of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Neoehrlichia mikurensis and Rickettsia helvetica in ticks collected from migratory birds in Norway. A total of 815 Ixodes ricinus ticks from 216 birds trapped at Lista Bird Observatory in southern Norway during spring and autumn migration in 2008 were analysed by real-time PCR. B. burgdorferi s. l. was the most prevalent pathogen, detected in 6.1% of the ticks. The prevalence of N. mikurensis, A. phagocytophilum and R. helvetica was 1.2%…
BBE31 from the Lyme disease agent Borrelia burgdorferi, known to play an important role in successful colonization of the mammalian host, shows the a…
2019
Abstract Lyme disease is a tick-borne infection caused by Borrelia burgdorferi sensu lato complex spirochetes. The spirochete is located in the gut of the tick; as the infected tick starts the blood meal, the spirochete must travel through the hemolymph to the salivary glands, where it can spread to and infect the new host organism. In this study, we determined the crystal structures of the key outer surface protein BBE31 from B. burgdorferi and its orthologous protein BSE31 (BSPA14S_RS05060 gene product) from B. spielmanii. BBE31 is known to be important for the transfer of B. burgdorferi from the gut to the hemolymph in the tick after a tick bite. While BBE31 exerts its function by intera…
αv-Class integrin binding to fibronectin is solely mediated by RGD and unaffected by an RGE mutation.
2020
Fibronectin (FN) is an essential glycoprotein of the extracellular matrix; binds integrins, syndecans, collagens, and growth factors; and is assembled by cells into complex fibrillar networks. The RGD motif in FN facilitates cell binding and fibrillogenesis through binding to α5β1 and αv-class integrins. However, whether RGD is the sole binding site for αv-class integrins is unclear. Most notably, substituting aspartate with glutamate (RGE) was shown to eliminate integrin binding in vitro, while mouse genetics revealed that FNRGE preserves αv-class integrin binding and fibrillogenesis. To address this conflict, we employed single-cell force spectroscopy, engineered cells, and RGD motif–defi…
Borrelia burgdorferi ārējās virsmas proteīnu BB0689 un BBA73 funkcionālie pētījumi
2015
Maģistra darbs veidots ar mērķi noskaidrot B. burgdorferi ārējās virsmas proteīnu BB0689 un BBA73 potenciālo lomu patogēna un saimniekorganisma mijiedarbībā, kas varētu paplašināt mūsu zināšanas par Laimboreliozes patoģenēzi. Borēlijas proteīnu un zīdītāju vai artropodu proteīnu iespējamā mijiedarbība ir noteikta, izmantojot Ni-NTA afinitātes hromatogrāfiju, proteīnu kompleksu imūnprecipitāciju (Co-Ip) un attālināto Western blotu. Konstatēto mijiedarbības partneru identifikācijai ir izmantota MALDI-TOF masas spektrometrija. Pētījuma rezultātā ir konstatēta BB0689 iespējamā saistība ar vairākiem zīdītāju proteīniem, savukārt BBA73 gadījumā ir novērota tā mijiedarbība ar Ixodes ērču proteīnie…
Laimas slimības ierosinātāja Borrelia burgdorferi ārējās virsmas proteīna BB0663 iegūšana un struktūras analīze
2019
Darba mērķis bija iegūt Laimas slimības izraisītāja Borrelia burgdorferi (B. burgdorgeri) celma B31 ārējās virsmas proteīna BB0663 struktūru un veikt šīs struktūras analīzi, lai iegūtu plašākas zināšanas par baktērijas patoģenēzes mehānismiem. Darba rezultātā BB0663 proteīns tika uzproducēts Escherichia coli šūnās, attīrīts un kristalizēts. Ar rengenstruktūranalīzes palīdzību tika iegūti šī kristāla difrakcijas dati. Izmantojot iegūtos datus, tika noteikta BB0663 proteīna 3D struktūra. Struktūras analīze parādīja, ka B. burgdorferi BB0663 proteīns ir līdzīgs baktērijas Novosphingobium aromaticivorans (N. aromaticivorans) proteīnam, kuram ir noteikta struktūra, bet nav zināma funkcija. Pētīj…
Unraveling the pleomorphic forms of Borrelia burgdorferi
2014
Borrelia burgdorferi bakteeri on puutiaisten välittämän borrelioosin taudinaiheuttaja. Tämä tavanomaisesti spirokeettana esiintyvä bakteeri kykenee vaihtamaan muotoaan ympäristöolosuhteiden muuttuessa epäsuotuisiksi. Borrelia-bakteerin eri esiintymismuotojen uskotaan olevan borrelioosin pitkittyneen taudinkuvan takana, minkä vuoksi näiden muotojen tutkiminen on tärkeää. Tämän pro gradu –työn tavoitteena oli tutkia B. burgdorferin pleomorfisia muotoja ja löytää muotoja erottavia morfologisia tekijöitä sekä eroja proteiiniekspressiossa ja borrelioosipotilasseerumivasteessa spirokeettojen ja pyöreän esiintymismuodon välillä. Olettamuksena oli, että konfokaalimikroskopialla muotojen väliltä löy…
Invariant natural killer T cells act as an extravascular cytotoxic barrier for joint-invading Lyme Borrelia
2014
CXCR6-GFP(+) cells, which encompass 70% invariant natural killer T cells (iNKT cells), have been found primarily patrolling inside blood vessels in the liver. Although the iNKT cells fail to interact with live pathogens, they do respond to bacterial glycolipids presented by CD1d on liver macrophage that have caught the microbe. In contrast, in this study using dual laser multichannel spinning-disk intravital microscopy of joints, the CXCR6-GFP, which also made up 60-70% iNKT cells, were not found in the vasculature but rather closely apposed to and surrounding the outside of blood vessels, and to a lesser extent throughout the extravascular space. These iNKT cells also differed in behavior,…
Variable exposure and immunological response to Lyme disease Borrelia among North Atlantic seabird species.
2008
Colonial seabirds often breed in large aggregations. These individuals can be exposed to parasitism by the tick Ixodes uriae , but little is known about the circulation of pathogens carried by this ectoparasite, including Lyme disease Borrelia . Here we investigated the prevalence of antibodies (Ab) against Borrelia burgdorferi sensu lato in seabird species sampled at eight locations across the North Atlantic. Using enzyme-linked immunosorbent assay tests, we found that the prevalence of anti- Borrelia Ab in adult seabirds was 39.6% on average (over 444 individuals), but that it varied among colonies and species. Common guillemots showed higher seroprevalence (77.1%±5.9) than black-legged …
Origin of the integrin-mediated signal transduction. Functional studies with cell cultures from the sponge Suberites domuncula
1999
Sponges (phylum Porifera) represent the phylogenetically oldest metazoan animals. Recently, from the marine sponge Geodia cydonium a first cDNA encoding a putative integrin receptor molecule was isolated. In the present study basic functional experiments have been conducted to test the hypothesis that in sponges integrin polypeptides also function as adhesion molecules and as outside-in signaling molecules. The sponge Suberites domuncula has been used for the experiments because from this sponge only has a cell culture been established. Here we report that aggregation factor (AF)-mediated cell-cell adhesion is blocked by the RGDS peptide which is known to interact with beta integrin. Both R…