Gentaur Pub

#34328698   2021/09/12 To Up

Insights into the ligand binding specificity of SREC-II (scavenger receptor expressed by endothelial cells).

SREC-II (scavenger receptor expressed by endothelial cells II) is a membrane protein encoded by the SCARF2 gene, with high homology to class F scavenger receptor SR-F1, but no known scavenging function. We produced the extracellular domain of SREC-II in a recombinant form and investigated its capacity to interact with common scavenger receptor ligands, including acetylated low-density lipoprotein (AcLDL) and maleylated or acetylated BSA (MalBSA or AcBSA). Whereas no binding was observed for AcLDL, SREC-II ectodomain interacted strongly with MalBSA and bound with high affinity to AcBSA, a property shared with the SR-F1 ectodomain. SREC-II ectodomain also interacted with two SR-F1-specific ligands, complement C1q and calreticulin, with affinities in the 100 nm range. We proceeded to generate a stable CHO cell line overexpressing full-length SREC-II; binding of MalBSA to these cells was significantly increased compared with nontransfected CHO cells. In contrast, no increase in binding could be detected for C1q and calreticulin. We show for the first time that SREC-II has the capacity to interact with the common scavenger receptor ligand MalBSA. In addition, our data highlight similarities and differences in the ligand binding properties of SREC-II in soluble form and at the cell surface, and show that endogenous protein ligands of the ectodomain of SREC-II, such as C1q and calreticulin, are shared with the corresponding domain of SR-F1.
Catherine Wicker-Planquart, Pascale Tacnet-Delorme, Laurence Preisser, Samy Dufour, Yves Delneste, Dominique Housset, Philippe Frachet, Nicole M Thielens

2205 related Products with: Insights into the ligand binding specificity of SREC-II (scavenger receptor expressed by endothelial cells).

96T100.00 ug100.00 ug1.00 flask1.00 flask1.00 flask1.00 flask1 ml50 ug1.00 flask1.00 flask1.00 flask

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#33847944   // To Up

Analysis of the Ligand Recognition Specificities of Human Ficolins Using Surface Plasmon Resonance.

Ficolins are innate immune recognition proteins involved in activation of the lectin complement pathway. These oligomeric lectin-like proteins are assembled from subunits consisting of a collagen-like triple helix and a trimeric fibrinogen-like recognition domain. In humans, three ficolins coexist: they differ in their ligand binding specificities, but share the capacity to associate with proteases through their collagen-like stalks and trigger complement activation. We describe methods to decipher the recognition specificities of ficolins, based on surface plasmon resonance, an optical technique allowing real-time and label-free monitoring of biomolecular interactions. This technique was mainly used to characterize and compare binding of the three recombinant full-length ficolins and of their isolated recognition domains to various immobilized BSA-glycoconjugates, acetylated BSA or biotinylated heparin. The avidity phenomenon that enhances the apparent affinity of interactions between oligomeric lectin-like proteins and the multivalent ligands is also discussed.
Nicole M Thielens, Evelyne Gout, Monique Lacroix, Jean-Baptiste Reiser, Christine Gaboriaud

1859 related Products with: Analysis of the Ligand Recognition Specificities of Human Ficolins Using Surface Plasmon Resonance.

100ul100 ug/vial10 296T250 ug100 1 mg100 ug/vial10ug

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#35423299   2021/02/22 To Up

Synthesis and spectral characterization of the first fluorescein-tagged iron(ii) clathrochelates, their supramolecular interactions with globular proteins, and cellular uptake.

A fluorescein-tagged iron(ii) cage complex was obtained in a moderate total yield using a two-step synthetic procedure starting from its propargylamine-containing clathrochelate precursor. An 11-fold decrease in fluorescence quantum yield is observed in passing from the given fluorescein-based dye to its clathrochelate derivative. An excitation energy transfer from the terminal fluorescent group of the macrobicyclic molecule to its quasiaromatic highly π-conjugated clathrochelate framework can explain this effect. The kinetics of the hydrolysis of the acetyl groups of acetylated fluorescein azide and its clathrochelate derivative in the presence of one equivalent of BSA evidenced no strong supramolecular host-guest interactions between BSA and the tested compounds. Study of a chemical stability of the deacetylated iron(ii) clathrochelate suggested the formation of a supramolecular 1 : 1 BSA-clathrochelate assembly. Moreover, an addition of BSA or HSA to its solution caused the appearance of strong clathrochelate-based ICD outputs. The fluorescence emission anisotropy studies also evidenced the supramolecular binding of the fluorescein-tagged iron(ii) clathrochelate to the BSA macromolecule, leading to a high increase in this type of anisotropy. Subcellular uptake of the fluorescein-tagged molecules was visualized using fluorescence microscopy and showed its distribution to be mainly in the cytosol without entering the nucleus or accumulating in any other organelle. An X-rayed crystal of the above propargylamide macrobicyclic precursor with a reactive terminal C[triple bond, length as m-dash]C bond contains the clathrochelate molecules of two types, A and B. The encapsulated iron(ii) ion in these molecules is situated in the center of its FeN-coordination polyhedron, the geometry of which is intermediate between a trigonal prism (TP) and a trigonal antiprism (TAP). The Fe-N distances vary from 1.8754(6) to 1.9286(4) Å and the heights of their distorted TP-TAP polyhedra are very similar (2.30 and 2.31 Å); their values of are equal to 25.3 and 26.6°. In this crystal, the molecules of types A and B participate in different types of hydrogen bonding, giving H-bonded clathrochelate tetramers through their carboxylic and amide groups, respectively; these tetramers are connected to H-bonded chains.
Roman O Selin, Insa Klemt, Viktor Ya Chernii, Mykhaylo Yu Losytskyy, Svitlana Chernii, Andrzej Mular, Elzbieta Gumienna-Kontecka, Vladyslava B Kovalska, Yan Z Voloshin, Anna V Vologzhanina, Pavel V Dorovatovskii, Andriy Mokhir

1992 related Products with: Synthesis and spectral characterization of the first fluorescein-tagged iron(ii) clathrochelates, their supramolecular interactions with globular proteins, and cellular uptake.

100ul1mg500 mg25 mg1010 mg100ul25 mg100ug 5 G 5 G

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#32041782   2020/02/10 To Up

C1q/TNF-Related Protein 6 Is a Pattern Recognition Molecule That Recruits Collectin-11 from the Complement System to Ligands.

C1q/TNF-related protein (CTRP) 6 is a member of the CTRP protein family associated with the regulation of cellular and endocrine processes. CTRP6 contains collagen and globular structures, resembling the pattern recognition molecules (PRMs) of the classical and lectin complement pathways. We expressed human CTRP6 in Chinese hamster ovary cells and investigated the binding to different putative ligands (acetylated BSA [AcBSA], zymosan, mannan, and LPS from and as well as to the monosaccharides l-fucose, d-mannose, -acetylglucosamine, -acetylgalactosamine, and galactose). Furthermore, we investigated the binding of CTRP6 to various Gram-negative bacteria as well as PRMs and enzymes of the lectin complement pathway. We found that CTRP6 bound to AcBSA and to a lesser extent to zymosan. Using EDTA as chelating agent, we observed an increased binding to AcBSA, zymosan and the two strains of LPS. We detected no binding to mannan and BSA. We identified l-fucose as a ligand for CTRP6 and that it bound to certain enteroaggregative and isolates, whereas to other bacterial isolates, no binding was observed. CTRP6 did not appear to interact directly with the activating enzymes of the lectin pathway; however, we could show the specific recruitment of collectin-11 and subsequent initiation of the complement cascade through deposition of C4. In conclusion, our results demonstrate the binding of CTRP6 to a variety of microbial and endogenous ligands identifying CTRP6 as a novel human lectin and PRM of importance for complement recognition and innate immunity.
Nikolaj Kirketerp-Møller, Rafael Bayarri-Olmos, Karen Angeliki Krogfelt, Peter Garred

2573 related Products with: C1q/TNF-Related Protein 6 Is a Pattern Recognition Molecule That Recruits Collectin-11 from the Complement System to Ligands.

100ug Lyophilized100ug Lyophilized100 ul0.1ml (1mg/ml) 100ul100ug Lyophilized100ug Lyophilized0.1ml (1mg/ml)100ul100ug Lyophilized100ug Lyophilized100ug Lyophilized

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#31936522   2020/01/09 To Up

Identification and Characterization of a β--Acetylhexosaminidase with a Biosynthetic Activity from the Marine Bacterium S66.

β--Acetylhexosaminidases are glycoside hydrolases (GHs) acting on -acetylated carbohydrates and glycoproteins with the release of -acetylhexosamines. Members of the family GH20 have been reported to catalyze the transfer of -acetylglucosamine (GlcNAc) to an acceptor, i.e., the reverse of hydrolysis, thus representing an alternative to chemical oligosaccharide synthesis. Two putative GH20 β--acetylhexosaminidases, Nah20A and Nah20B, encoded by the marine bacterium S66, are distantly related to previously characterized enzymes. Remarkably, Nah20A was located by phylogenetic analysis outside clusters of other studied β--acetylhexosaminidases, in a unique position between bacterial and eukaryotic enzymes. We successfully produced recombinant Nah20A showing optimum activity at pH 6.0 and 50 °C, hydrolysis of GlcNAc β-1,4 and β-1,3 linkages in chitobiose (GlcNAc) and GlcNAc-1,3-β-Gal-1,4-β-Glc (LNT2), a human milk oligosaccharide core structure. The kinetic parameters of Nah20A for -nitrophenyl-GlcNAc and -nitrophenyl-GalNAc were highly similar: / being 341 and 344 mM s, respectively. Nah20A was unstable in dilute solution, but retained full activity in the presence of 0.5% bovine serum albumin (BSA). Nah20A catalyzed the formation of LNT2, the non-reducing trisaccharide β-Gal-1,4-β-Glc-1,1-β-GlcNAc, and in low amounts the β-1,2- or β-1,3-linked trisaccharide β-Gal-1,4(β-GlcNAc)-1,-Glc by a transglycosylation of lactose using 2-methyl-(1,2-dideoxy-α-d-glucopyrano)-oxazoline (NAG-oxazoline) as the donor. Nah20A is the first characterized member of a distinct subgroup within GH20 β--acetylhexosaminidases.
Triinu Visnapuu, David Teze, Christian Kjeldsen, Aleksander Lie, Jens Øllgaard Duus, Corinne André-Miral, Lars Haastrup Pedersen, Peter Stougaard, Birte Svensson

1197 related Products with: Identification and Characterization of a β--Acetylhexosaminidase with a Biosynthetic Activity from the Marine Bacterium S66.

1 kit1,000 tests200 assays2x96 well plates100ug100ug96 assays 1 mg100 assays 96 Tests

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#31336116   2019/07/20 To Up

Preparation and properties of hydrophobic films based on acetylated broken-rice starch nanocrystals for slow protein delivery.

Native and acetylated broken-rice starches (nanocrystals) with different degrees of substitution (DS) and their corresponding films were individually prepared, and the drug release profiles, weight loss, solubility and dispersion and surface morphology were comparatively studied. Bovine serum albumin (BSA) was used as a model drug. Acetylated native starch (ANS) DS 2.58, acetylated starch nanocrystals (ASN) DS 0.98, ASN DS 1.86, and ASN DS 2.72 were observed to be very soluble in chloroform. BSA was released rapidly from the native rice starch (NS) and ANS DS 2.58 films. ASN with high DS significantly slowed down the release of BSA from films, the percentages of BSA released from film ASN DS 2.72 only reached to 13% after 3.5 weeks release, and the release data followed Korsmeyer-Peppas equation. Further studies reveal that the particle size of ASN DS 2.72 was smallest, and the weight loss of ASN DS 2.72 film was lowest. The results demonstrate that acetylation and nanometer particle form of rice starch film can effectively retard protein drug release, and the prepared films based on ASN with high DS from broken rice may be suitable for the controlled protein delivery.
Huaxi Xiao, Fan Yang, Qinlu Lin, Qian Zhang, Weize Tang, Lin Zhang, Dong Xu, Gao-Qiang Liu

1397 related Products with: Preparation and properties of hydrophobic films based on acetylated broken-rice starch nanocrystals for slow protein delivery.

1 mg100ul10 mg0.1 mg100preparations0.2 mg100ug100ug0.1 mg25 mg100ul

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#30459417   2018/11/20 To Up

Chemical and sensorial investigation of in-mouth sensory properties of grape anthocyanins.

Anthocyanins are water-soluble pigments found in the cell vacuoles of fruits and flowers, performing several roles from insects attraction to stress protection. Their antioxidant activity contributes to human health, and consuming plant-derived products provides their higher source in the diet. Although their colour and nutritional features, their contribution to sensory properties of foods has not been widely investigated. In wine, preferences are connected with sensory attributes of colour, aroma, taste, and mouthfeel. In this study, grape anthocyanin extracts (TAE) were fractionated using centrifugal partition chromatography (CPC) and preparative HPLC in three fractions, i.e glucoside (GF), acetylated (AF) and cinnamoylated (CF) anthocyanins. Sensory properties were investigated by chemical analysis, as reactivity towards bovin serum albumin (BSA) and salivary proteins, and in tasting sessions to assess anthocyanins best estimated thresholds (BET) in wine-like solution. Anthocyanins reacted with both BSA and salivary proteins, but to different extents, because higher interaction between salivary proteins and anthocyanins were found. Cinnamoylated anthocyanins are the most reactive to salivary proteins. Tasting sessions suggested an involvement of anthocyanins as in-mouth contributors in wine, since their BETs were 255, 297, 68, and 58 mg/L for TAE, GF, AF, and CF, respectively, and the descriptors reported were astringency and bitterness.
M A Paissoni, P Waffo-Teguo, W Ma, M Jourdes, L Rolle, P -L Teissedre

2406 related Products with: Chemical and sensorial investigation of in-mouth sensory properties of grape anthocyanins.

5 G1 mg200ug10 mg 50 UG1000 tests100ug200ul25 mg50 ug 10 mg

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#29385411   // To Up

Palmitic acid induces ceramide accumulation, mitochondrial protein hyperacetylation, and mitochondrial dysfunction in porcine oocytes.

Low oocyte quality is a possible causal factor of obesity-induced infertility. High palmitic acid (PA) concentration in follicular fluid is a crucial feature noted in obese women. This study examined how high PA concentration reduced mitochondrial quality in oocytes and investigated a possible countermeasure against mitochondrial dysfunction. Cumulus cell-oocyte complexes were obtained from the ovaries of gilts, and incubated in medium containing PA (0.5 mM) or vehicle (BSA) for 44 h. Culturing oocytes at high PA concentration induced mitochondrial dysfunction determined by high reactive oxygen species and low ATP content in oocytes. Furthermore, high PA levels increased mitochondrial acetylation levels determined by a high degree of co-localization of TOMM20 and acetylated-lysine. In addition, high PA levels reduced the expression of Sirtuin 3 (SIRT3) and phosphorylated AMP-activated protein kinase (AMPK), while the AMPK activator, AICAR, restored mitochondrial function as well as oocyte ability and reduced the acetylation of mitochondrial protein. Supplementation of culture medium with dorsomorphin dihydrochloride (an AMPK inhibitor) reduced mitochondrial function and increased mitochondrial protein acetylation. Treatment of oocytes with LB100 (an inhibitor of AMPK dephosphorylation) reduced mitochondrial acetylation levels and restored mitochondrial function. Furthermore, high PA levels increased ceramide accumulation in oocytes, and addition of ceramide to the culture medium also induced mitochondrial dysfunction and increased mitochondrial acetylation. This detrimental effect of ceramide was diminished by AICAR treatment of oocytes. Our results indicated that PA induces ceramide accumulation and downregulates the AMPK/SIRT3 pathway causing mitochondrial protein hyperacetylation and dysfunction in oocytes.
Nobuhiko Itami, Koumei Shirasuna, Takehito Kuwayama, Hisataka Iwata

2436 related Products with: Palmitic acid induces ceramide accumulation, mitochondrial protein hyperacetylation, and mitochondrial dysfunction in porcine oocytes.

0.1 ml 100ul100ug96tests100ug1 Set1 Set501 Set1 Set1 Set

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