Search results for "Sulfation"
showing 10 items of 26 documents
Dehydroepiandrosterone Induction of the Abcd2 and Abcd3 Genes encoding peroxisomal ABC Transporters
2003
Dehydroepiandrosterone (DHEA) is a peroxisome proliferator known to increase the expression of the genes encoding the peroxisomal s-oxidation enzymes in rodents. Using RT-PCR, we analysed the expression of the Abcd2 and Abcd3 genes encoding the peroxisomal ABC transporters ALDRP (ALD related protein) and PMP70 (70 kDa peroxisomal membrane protein) in primary cultures of rats hepatocytes treated with sulfated DHEA. We observed a time (12-72h) and dose (125-500μM) dependent increase in the expression of both genes.
Activation of the alternative pathway of complement: efficient fluid-phase amplification by blockade of the regulatory complement protein β1H through…
1981
Current concepts of activation of the alternative pathway of complement (APC) focus on the central role of an amplification mechanism triggered by C3b which is covalently bound to the surfact of activating substances. Using sulfated polyanions as model substances, an efficient fluid-phase activation of complement is demonstrated in contrast to solid-phase activation. It is shown that particulate high-molecular weight sulfated polyanions are capable of reversible binding the guinea pig and human regulatory protein beta1H. This fixation leads to an extensive activation of C3 and factor B because the regulatory function of beta1H is blocked in the fluid-phase C3b-dependent amplification system…
Structural determination of the lipo-chitin oligosaccharide nodulation signals produced by Rhizobium giardinii bv. giardinii H152
2003
Abstract Rhizobium giardinii bv. giardinii is a microsymbiont of plants of the genus Phaseolus and produces extracellular signal molecules that are able to induce deformation of root hairs and nodule organogenesis. We report here the structures of seven lipochitooligosaccharide (LCO) signal molecules secreted by R. giardinii bv. giardinii H152. Six of them are pentamers of GlcNAc carrying C 16:0 , C 18:0 , C 20:0 and C 18:1 fatty acyl chains on the non-reducing terminal residue. Four are sulfated at C-6 of the reducing terminal residue and one is acetylated in the same position. Six of them are N -methylated on the non-reducing GlcN residue and all the nodulation factors are carbamoylated o…
Reply to "Heparan Sulfate in Baculovirus Binding and Entry of Mammalian Cells"
2014
(1), we investigated the interaction ofbaculovirus and mammalian cell surface heparan sulfate pro-teoglycans (HSPG). The data show that baculovirus requiresHSPG sulfation, particularly N- and 6-O-sulfation, to bind andtransduce mammalian cells. We also show that baculovirus asso-ciates specifically with syndecan-1 (SDC-1) but not with othersyndecans or glypicans.As discussed in the article, HS has previously been shown to beinvolved in glycoprotein 64 (gp64)-mediated baculovirus bindingonto mammalian cells. Heparin and heparinase I and II treatmentof cells have also been shown to prevent the virus binding (2, 3).The role of HS in baculovirus entry was further studied in ourarticle (1). Bindi…
Sulfotransferase-mediated activation of mutagens studied using heterologous expression systems
1998
Abstract Sulfation is a common final step in the biotransformation of xenobiotics and is traditionally associated with inactivation. However, the sulfate group is electron-withdrawing and may be cleaved off heterolytically in some molecules leading to electrophilic cations which may form adducts with DNA and other important cellular structures. Since endogenous sulfotransferases do not appear to be expressed in indicator cells of standard mutagenicity tests, rat and human sulfotransferases have been stably expressed in his−Salmonella typhimurium strain TA1538 and Chinese hamster V79 cells. Using these recombinant indicator cells, sulfotransferase-dependent genotoxic activities were detected…
Sulphation and Hydrolysis Improvements of Bioactivities, and Immuno-Modulatory Properties of Edible Amanita hemibapha Subspecies javanica (Corner and…
2021
In this study, the mucilage polysaccharide (MP) from Amanita hemibapha subspecies javanica was prepared by hot water extraction and ethanol precipitation and then fractionated using anion-exchange chromatography equipped with a DEAE Sepharose fast flow column. The most immune-enhancing polysaccharide fraction 2 (MPF2) was subjected to a structural modification such as hydrolysis or over-sulphation. The sulphate and molecular weight (Mw) of over-sulphated (OS1-3) and hydrolysed (HS1-3) derivatives of MPF2 differed between 9.85% and 14.2% and 32.8 and 88.1 × 103 g/mol, respectively. Further, the immune-enhancing properties of MPF2 and its derivatives were tested on RAW264.7 and NK cells throu…
Mode of interaction of different polyanions with the first (), the second (C2) and the fourth (C4) component of complement—II
1976
Abstract Dextran sulfate, polyvinyl sulfate, liquoid, heparin and Sp 54, ∗ (a pentosanpoly-sulfoester) prevented the uptake of C2 by EAC4b. In contrast to EAC 4 b 2 a , treatment of EAC4b2 with polyanions led to dissociation into EAC4b and C2. The inhibition of C2 uptake by polyanions could be reduced by increasing magnesium concentration to levels which are normally inhibitory, suggesting that Mg ++ ions are sequestered by these sulfated polyanions.
Fast evaluation of enantioselective drug metabolism by electrophoretically mediated microanalysis: application to fluoxetine metabolism by CYP2D6.
2013
In this work, a capillary electrophoretic methodology for the enantioselective in vitro evaluation of drugs metabolism is applied to the evaluation of fluoxetine (FLX) metabolism by cytochrome 2D6 (CYP2D6). This methodology comprises the in-capillary enzymatic reaction and the chiral separation of FLX and its major metabolite, norfluoxetine enantiomers employing highly sulfated β-CD and the partial filling technique. The methodology employed in this work is a fast way to obtain a first approach of the enantioselective in vitro metabolism of racemic drugs, with the additional advantage of an extremely low consumption of enzymes, CDs and all the reagents involved in the process. Michaelis-Men…
Characterization of thyroid hormone sulfotransferases
1998
Sulfation is an intriguing pathway of thyroid hormone metabolism since it facilitates the degradation of the hormone by the type I deiodinase (D1). This study reports the preliminary characterization of iodothyronine sulfotransferase activities of rat and human liver cytosol and recombinant rSULT1C1 and hSULT1A1 isoenzymes. All these enzyme preparations catalyzed the sulfation of--in decreasing order of efficiency--3,3'-diiodothyronine (3,3'-T2)3,3',5-triiodothyronine (T3) approximately 3,3',5'-triiodothyronine (rT3)thyroxine (T4). 3,3'-T2 sulfotransferase activity was found to be higher in male than in female rat liver, which has also been shown by others for the expression of rSULT1A1 and…
The role of biosilica in the osteoprotegerin/RANKL ratio in human osteoblast-like cells
2010
Abstract Earlier studies have demonstrated that biosilica, synthesized by the enzyme silicatein, induces hydroxyapatite formation in osteoblast-like SaOS-2 cells. Here we study the effect of biosilica on the expressions of osteoprotegerin [OPG] and the receptor activator for NF-κB ligand [RANKL] in the SaOS-2 cell model. We show that during growth of SaOS-2 cells on biosiliceous matrices hydroxyapatite formation is induced, while syntheses of cartilaginous proteoglycans and sulfated glycosaminoglycans are down-regulated. Furthermore, quantitative real-time RT-PCR analysis revealed a strong time-depended increase in expression of OPG in biosilica exposed SaOS-2 cells while the steady-state e…