Search results for "oligopeptides"
showing 10 items of 136 documents
In vitro T-cell immunogenicity of oligopeptides derived from the region 92-110 of the 16-kDa protein ofMycobacterium tuberculosis
2004
The 16-kDa protein of Mycobacterium tuberculosis provokes specific immune responses; it is thus a target for the development of peptide-based diagnostic reagents and subunit vaccines. Previous studies have demonstrated the presence of several regions containing murine and human T-cell epitopes. Within the 91–110 immunodominant domain, we found that peptides comprising the sequence of 91SEFAYGSFVRTVSL104 elicit specific T-cell responses in both human T-cell clones and human peripheral blood mononuclear cells (PBMC) from PPD+ (purified protein derivative) individuals. Elongation of this peptide towards the C-terminal end did not provide more effective peptides, but the removal of residue 91Se…
Factor VIIa-induced interaction with integrin controls the release of tissue factor on extracellular vesicles from endothelial cells.
2019
Essentials Prothrombotic extracellular vesicles (EV) carry agonist pathway-specific proteomes Agonists for protease activated receptor (PAR) 2 signaling have distinct effects on EV composition PAR2 signaling rapidly generates prothrombotic EV and slowly EV with inactive tissue factor (TF) FVIIa integrin ligation restricts TF incorporation into EV from endothelial cells SUMMARY: Background Cell injury signal-induced activation and release of tissue factor (TF) on extracellular vesicles (EVs) from immune and vessel wall cells propagate local and systemic coagulation initiation. TF trafficking and release on EVs occurs in concert with the release of cell adhesion receptors, including integrin …
Improved Expression of His6-Tagged Strictosidine Synthase cDNA for Chemo-Enzymatic Alkaloid Diversification
2010
Strictosidine synthase (STR1) catalyzes the stereoselective formation of 3alpha(S)-strictosidine from tryptamine and secologanin. Strictosidine is the key intermediate in the biosynthesis of 2,000 plant monoterpenoid indole alkaloids, and it is a key precursor of enzyme-mediated synthesis of alkaloids. An improved expression system is described which leads to optimized His(6)-STR1 synthesis in Escherichia coli. Optimal production of STR1 was achieved by determining the impact of co-expression of chaperones pG-Tf2 and pG-LJE8. The amount and activity of STR1 was doubled in the presence of chaperone pG-Tf2 alone. His(6)-STR1 immobilized on Ni-NTA can be used for enzymatic synthesis of stricto…
Theoretical study of the interaction between sodium ion and a cyclopeptidic tubular structure.
2007
DFT calculations have been carried out to describe the pathway of a sodium ion along the stacking direction of a tubular structure set up by five cyclopeptidic units, which can be considered a suitable model of a hollow tubular structure of indefinite length. A lattice of points inside the tubular structure is defined and the DFT interaction energy values with a sodium ion are obtained. The data allow predicting a zigzag path of the ion inside the hosting structure. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
A tyrosinase nonapeptide presented by HLA-B44 is recognized on a human melanoma by autologous cytolytic T lymphocytes
1996
The human tyrosinase gene has been reported previously to code for two distinct antigens recognized on HLA-A2 melanoma cells by autologous cytolytic T lymphocytes (CTL). By stimulating lymphocytes of melanoma patient MZ2 with a subclone of the tumor cell line of this patient, we obtained a CTL clone that lysed this subclone but did not lyse other subcloncs of the Same melanoma cell line. The sensitive melanoma subclone was found to express a much higher level of tyrosinase than the others, suggesting that the antigen recognized bv the CTL might be encoded by tyrosinase. Transfection of a tyrosinase cDNA demonstrated that the CTL clone indeed recognized a tyrosinase product presented by HLA-…
Wet-chemical approach for the cell-adhesive modification of polytetrafluoroethylene
2011
Polytetrafluoroethylene (PTFE), a frequently utilized polymer for the fabrication of synthetic vascular grafts, was surface-modified by means of a wet-chemical process. The inherently non-cell-adhesive polymer does not support cellular attachment, a prerequisite for the endothelialization of luminal surface grafts in small diameter applications. To impart the material with cell-adhesive properties a treatment with sodium-naphthalene provided a basis for the subsequent immobilization of the adhesion promoting RGD-peptide using a hydroxy- and amine-reactive crosslinker. Successful conjugation was shown with cell culture experiments which demonstrated excellent endothelial cell growth on the m…
Integrin-dependent and -independent functions of astrocytic fibronectin in retinal angiogenesis
2011
Fibronectin (FN) is a major component of the extracellular matrix and functions in cell adhesion, cell spreading and cell migration. In the retina, FN is transiently expressed and assembled on astrocytes (ACs), which guide sprouting tip cells and deposit a provisional matrix for sprouting angiogenesis. The precise function of FN in retinal angiogenesis is largely unknown. Using genetic tools, we show that astrocytes are the major source of cellular FN during angiogenesis in the mouse retina. Deletion of astrocytic FN reduces radial endothelial migration during vascular plexus formation in a gene dose-dependent manner. This effect correlates with reduced VEGF receptor 2 and PI3K/AKT signalli…
A proctolin-like peptide is regulated after baculovirus infection and mediates in caterpillar locomotion and digestion
2022
Baculoviruses constitute a large group of invertebrate DNA viruses, predominantly infecting larvae of the insect order Lepidoptera. During a baculovirus infection, the virus spreads throughout the insect body producing a systemic infection in multiple larval tissues, included the central nervous system (CNS). As a main component of the CNS, neuropeptides are small protein-like molecules functioning as neurohormones, neurotransmitters, or neuromodulators. These peptides are involved in regulating animal physiology and behavior and could be altered after baculovirus infection. In this study, we have investigated the effect of Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) infection …
Evolution of Cell Adhesion Systems: Evidence for Arg-Gly-Asp-Mediated Adhesion in the Protozoan Neoparamoeba aestuarina
1995
Developmental processes in multicellular organisms require structural elements, such as adhesion molecules, to stabilize cells at functional positions. In vertebrates, a series of extracellular matrix proteins, e.g. fibronectin and laminin, are involved in cell adhesion. These proteins contain Arg-Gly-Asp [RGD] at their binding sites. Here we show that at concentrations above 2 mM the peptide GRGDSPK, comprising the tripeptide RGD (Arg-Gly-Asp), prevents the adhesiveness of cells of the marine amoeba Neoparamoeba aestuarina. In addition, elevated levels of GRGDSPK cause cells to alter their shapes from those with digitiform subpseudopodia to rounded cells with small lobed pseudopodia. These…
Multifibrillar bundles of a self-assembling hyaluronic acid derivative obtained through a microfluidic technique for aortic smooth muscle cell orient…
2018
A hyaluronic acid derivative that is able to physically crosslink in a saline aqueous environment was employed for the production of fibers with a mean diameter of 50 μm using a microfluidic technique. The microfibers were collected in a tailored rotating collector and assembled to form multifibrillar bundles. The orientation of the microfibers on the collected bundles was evaluated by microCT analysis. The bundles were biofunctionalized by physical addition of fibronectin or chemical tethering of a cyRGDC peptide to achieve control of Aortic Smooth Muscle Cell (AoSMC) attachment, elongation and alignment. The mechanical performances of these bundles were evaluated by elongation tests, rela…