Search results for "binding"
showing 10 items of 3896 documents
The influence of internal degrees of freedom on the unimolecular decay of the molecule–cluster compound Au8+CH3OH
2002
Time-resolved photodissociation measurements of the sequential reaction Au8+CH3OH→Au8+→Au7+ and the direct reaction Au8+→Au7+ have been performed for several excitation energies. The production rates and yields of the final state Au7+ in the sequential process are strongly influenced by the excitation energy deposited into the evaporated methanol molecule during the initial fragmentation step. Both the rate constants and yields can be fitted with a single parameter, the cluster–methanol binding energy.
Rate-retarding effects of mixed anionic/non-ionic micelles on the alkaline hydrolysis of the chloropentamminocobalt(III) complex
2006
Abstract Rate data for the alkaline hydrolysis of the chloropentaamminecobalt(III) cation in the presence of mixed micelles composed of (i) anionic sodium decylsulphate (SDeS) and non-ionic dodecylpenta(oxyethylene glycol) monoether (C 12 E 5 ) surfactants and (ii) anionic sodium perfluorooctanoate (SPFO) and non-ionic C 12 E 5 surfactants has been obtained at T 298 K and constant electrolyte concentration 0.08 mol dm −3 ([NaOH] = 0.01 mol dm −3 , [NaClO 4 ] = 0.07 mol dm −3 ) over a wide range of total surfactant concentration ( C t ) and anionic mole fraction ( χ ). The critical micelle concentrations (c.m.c.s) of the mixed micelles have been determined over the entire χ range by means of…
Expression of the fibrinogen binding mannoprotein and the laminin receptor of Candida albicans in vitro and in infected tissues.
1996
We have previously reported a 37 kDa laminin-binding protein (p37) and a 58 kDa fibrinogen-binding mannoprotein (mp58) on the surface of Candida albicans. A few yeast cells expressed both functional receptors at the surface while germ tubes expressed a functional mp58 fibrinogen but not a functional p37 laminin receptor. These receptors were heterogeneously dispersed at the surface as shown by binding of rabbit antiserum to mp58 (PAb anti-mp58) and antiserum to the human high affinity laminin receptor. In this report we have used a dual fluorescence technique to determine if the two receptors colocalize, perhaps as part of a receptor complex. Fibrinogen was used as a probe for mp58 and poly…
A New Type of Cytokine Receptor Antagonist Directly Targeting gp130
1998
The interleukin-6-type family of cytokines bind to receptor complexes that share gp130 as a common signal-transducing subunit. So far, receptor antagonists for interleukin-6-type cytokines have been constructed that still bind to the specific ligand binding subunit of the receptor complex, but have lost the ability to stimulate gp130. Such receptor antagonists compete for a specific receptor of a member of the cytokine family. Interleukin-6 only binds to gp130 when complexed with the interleukin-6 receptor that exists as a membrane bound and soluble molecule. Here we have constructed fusion proteins that consist of the soluble form of the human interleukin-6 receptor covalently linked to in…
Reconstitution of vesicular transport to Rab11-positive recycling endosomes in vitro.
2003
Rab GTPases are key regulators of vesicular protein transport in both the endocytic and exocytic pathways. In endocytosis and recycling, Rab11 plays a role in receptor recycling to plasma membrane via the pericentriolar recycling compartment. However, little is known about the molecular requirements and partners that promote transport through Rab11-positive recycling endosomes. Here, we report a novel approach to reconstitute transport to immunoabsorbed recycling endosomes in vitro. We show that transport is temperature-, energy-, and time-dependent and requires the presence of Rab proteins, as it is inhibited by the Rab-interacting protein Rab GDP-dissociation inhibitor that removes Rab pr…
The N-terminal Amino Group of [Tyr8]Bradykinin Is Bound Adjacent to Analogous Amino Acids of the Human and Rat B2 Receptor
1996
To obtain data of the bradykinin B2 receptor's agonist binding site, we used a combined approach of affinity labeling and "immunoidentification" of receptor fragments generated by cyanogen bromide cleavage. Domain-specific antibodies to the various extracellular receptor domains were applied to detect receptor fragments with covalently attached [125I-Tyr8]bradykinin. As a cross-linker we used the homobifunctional reagent disuccinimidyl tartarate (DST), which reacts preferentially with primary amines. With this technique a [125I-Tyr8]bradykinin-labeled receptor fragment derived from the third extracellular domain was identified. The epsilon-amino group of lysine (Lys172) of the human B2 rece…
The Ability of Variant Peptides to Reverse the Nonresponsiveness of T Lymphocytes to the Wild-Type Sequence p53264–272 Epitope
2002
Abstract Recently, we observed that CTL specific for the wild-type (wt) sequence p53264–272 peptide could only be expanded ex vivo from PBMC of a subset of the HLA-A2.1+ normal donors or cancer patients tested. Surprisingly, the tumors of the responsive patients expressed normal levels of wt p53 and could be considered unlikely to present this epitope. In contrast, tumors of nonresponsive patients accumulated mutant p53 and were more likely to present this epitope. We sought to increase the responsive rate to the wt p53264–272 peptide of PBMC obtained from normal donors and patients by identifying more immunogenic variants of this peptide. Two such variants were generated by amino acid exch…
Second-generation Langerhans cells originating from epidermal precursors are essential for CD8+ T cell priming.
2014
Abstract In vivo studies questioned the ability of Langerhans cells (LCs) to mediate CD8+ T cell priming. To address this issue, we used intradermal immunization with plasmid DNA, a system in which activation of CD8+ T cells depends on delayed kinetics of Ag presentation. We found that dendritic cells (DCs) located in the skin at the time of immunization have limited ability to activate CD8+ T cells. This activity was mediated by a second generation of DCs that differentiated in the skin several days after immunization, as well as by lymph node–resident DCs. Intriguingly, CD8+ T cell responses were not affected following treatment with clodronate liposomes, immunization of CCR2−/− mice, or …
PAR1 signaling regulates the retention and recruitment of EPCR-expressing bone marrow hematopoietic stem cells
2015
Retention of long-term repopulating hematopoietic stem cells (LT-HSCs) in the bone marrow is essential for hematopoiesis and for protection from myelotoxic injury. We report that signaling cascades that are traditionally viewed as coagulation related also control retention of endothelial protein C receptor-positive (EPCR(+)) LT-HSCs in the bone marrow and their recruitment to the blood via two pathways mediated by protease activated receptor 1 (PAR1). Thrombin-PAR1 signaling induces nitric oxide (NO) production, leading to EPCR shedding mediated by tumor necrosis factor-α-converting enzyme (TACE), enhanced CXCL12-CXCR4-induced motility and rapid stem and progenitor cell mobilization. Conver…
Alcadein cleavages by amyloid beta-precursor protein (APP) alpha- and gamma-secretases generate small peptides, p3-Alcs, indicating Alzheimer disease…
2009
Alcadeins (Alcs) constitute a family of neuronal type I membrane proteins, designated Alc(alpha), Alc(beta), and Alc(gamma). The Alcs express in neurons dominantly and largely colocalize with the Alzheimer amyloid precursor protein (APP) in the brain. Alcs and APP show an identical function as a cargo receptor of kinesin-1. Moreover, proteolytic processing of Alc proteins appears highly similar to that of APP. We found that APP alpha-secretases ADAM 10 and ADAM 17 primarily cleave Alc proteins and trigger the subsequent secondary intramembranous cleavage of Alc C-terminal fragments by a presenilin-dependent gamma-secretase complex, thereby generating "APP p3-like" and non-aggregative Alc pe…