Search results for "Branes"
showing 5 items of 525 documents
Determination of glyphosate and its metabolite aminomethylphosphonic acid in fruit juices using supported-liquid membrane preconcentration method wit…
2005
Abstract The application of supported-liquid membrane (SLM) technique for effective extraction of N -(phosphonomethyl)glycine (glyphosate) and its primary metabolite aminomethylphosphonic acid (AMPA) from juices (orange, grapefruit, apple and blackcurrant) in combination with HPLC-UV detection after derivatization with p -toluenesulphonyl chloride (TsCl) is presented. The influence of various parameters such as the composition of acceptor phase, flow-rate, concentration of analytes, on the performance of extraction procedure, was studied. It was shown that by appropriate manipulation of SLM parameters the level of detection could be significantly improved. The influence of SLM conditions on…
From endosomes onwards : membranes, lysosomes and viral capsid interactions
2009
Kirsi Pakkanen haki väitöstutkimuksessaan monitieteellisen lähestymistavan avulla uusia näkökulmia virustutkimukseen. Tutkimus tuo uutta tietoa lipidikalvojen merkityksestä viruksen ja viruksen isäntäsolun elämässä. Tutkimuksessa selvisi, että koiran parvovirus, jota tutkimuksessa käytettiin mallina parvoviruksille ja yleisemmin vaipattomille viruksille, tarvitsee tietynlaisia isäntäsolun lipidikalvojen ominaisuuksia voidakseen vapautua solunsisäisten endosomirakkuloiden sisältä. Erityisen tärkeää tässä vapautumisessa näytti olevan kalvojen juoksevuus sekä jäykkien alueiden hallittu järjestäytyminen kolesterolin avulla. Hyödyntämällä molekyylejä, lääkeaineita, jotka muuttavat kolesteroliavu…
The Extracellular δ-Domain is Essential for the Formation of CD81 Tetraspanin Webs
2014
AbstractCD81 is a ubiquitously expressed member of the tetraspanin family. It forms large molecular platforms, so-called tetraspanin webs that play physiological roles in a variety of cellular functions and are involved in viral and parasite infections. We have investigated which part of the CD81 molecule is required for the formation of domains in the cell membranes of T-cells and hepatocytes. Surprisingly, we find that large CD81 platforms assemble via the short extracellular δ-domain, independent from a strong primary partner binding and from weak interactions mediated by palmitoylation. The δ-domain is also essential for the platforms to function during viral entry. We propose that, ins…
In vitro studies on the activation of the hepatitis C virus NS3 proteinase by the NS4A cofactor.
1996
AbstractProteolytic processing of the nonstructural proteins of the hepatitis C virus (HCV) is mediated by two viral proteinases: the NS2-3 proteinase cleaving at the NS2/3 junction and the NS3 serine-type proteinase responsible for processing at the NS3/4A, NS4A/B, NS4B/5A, and NS5A/B sites. Activity of the NS3 proteinase is modulated by NS4A. In the absence of this cofactor processing at the NS3-dependent sites does not occur or, in the case of the NS5A/B junction, is poor but increased when NS4A is present. Although recent studies demonstrated that proteinase activation requires direct interaction between NS3 and NS4A, the mechanism by which NS4A exerts the activation function is not kno…