Search results for "Linker"
showing 10 items of 100 documents
Specific interaction of desthiobiotin lipids and water-soluble biotin compounds with streptavidin
1991
As shown for biotin lipids (Ref. 1), the formation of perfect 2-D crystalline streptavidin domains can also be observed in the plane of desthiobiotin lipid monolayers. The binding constant of streptavidin with desthiobiotin (Ka = 5·1013 mol−1) is lower than that with biotin (Ka = 1015 mol−1) (Ref. 2). By adding free biotin into the subphase a competitive replacement and a detaching of the streptavidin domains from the desthiobiotin lipid monolayer takes place. Streptavidin domains built at receptor lipid monolayers are still functional. As could be shown, there are two biotin binding sites at each protein molecule that are fully accessible to biotin (Ref. 1). This can be proven by the inter…
Synthesis and Spectral and Structural Characterization of a New Series of Bis-Strapped Chiral Porphyrins Derived from L-Proline
2001
International audience; New chiral porphyrins were obtained in reasonable yields in three steps, starting from the áâáâ atropisomer of mesotetrakis(o-aminophenyl)porphyrin (TAPP). These potential catalysts for the enantioselective epoxidation of alkenes were obtained by the reaction of different linkers on the same Lprolinoyl-picket porphyrin. Their 1H NMR spectral characteristics, as well as the crystal structure of one of them, clearly indicate that the orientation of the proline cycle depends on the linker used to tether the two pickets on each side of the porphyrin. The same linker is employed for both sides of the porphyrin; hence the resulting D2-symmetric superstructure.
Tetrazīna ciklu saturoši proteīnu linkeri
2022
Proteīnu linkeri. Augšpuls H., zinātniskais vadītājs doc. Kļimenkovs I., bakalaura darbs, 3 lappuses, 27 attēli, 27 literatūras avoti, 2 pielikumi. Latviešu valodā. PROTEĪNU LINKERI, GABRIELA METODE, AZĪDI, AIZSARGGRUPAS, AMĪDU SINTĒZE Bakalura darba ietvaros veikta proteīnu linkera sintēze ar aizsargātu aldehīdgrupu. No 1,8-dibromoktāna sintezēts oktān-1,8-diamīns, kam viena aminogrupa aizsargāta ar Boc-grupu. Aizsargātais diamīns acilēts ar (4-azidofenil)etiķskābi, kas iegūta no (4-aminofenil)etiķskābes. No acilētā produkta ieguva triazolu, no kura tālāk tika iegūts aizsargātais tetrazīna ciklu saturošais proteīnu linkeris.
Use of the Transglutaminase Reaction To Study the Dissociation of Histone N-Terminal Tails from DNA in Nucleosome Core Particles
1997
We have recently shown that core histones are glutaminyl substrates for transglutaminase (TGase) and that when native nucleosome cores are incubated with monodansylcadaverine (DNC) as donor amine, this fluorescent probe is incorporated into Gln5 and Gln19 of H3 and in Gln22 of H2B [Ballestar et al. (1996) J. Biol. Chem. 271, 18817-18825]. In the present paper, we report that the cause by which Gln22 of H2B is modified in nucleosomes but not in the free histone is the interaction of the region containing that glutamine with DNA. We have used the specificity of the TGase reaction to study the changes induced by increasing ionic strength in the interaction between the histone N-terminal tails …
The (2-phenyl-2-trimethylsilyl)ethyl-(PTMSEL)-linker in the synthesis of glycopeptide partial structures of complex cell surface glycoproteins.
2003
The (2-phenyl-2-trimethylsilyl)ethyl-(PTMSEL) linker represents a novel fluoride-sensitive anchor for the solid-phase synthesis of protected peptides and glycopeptides. Its cleavage is achieved under almost neutral conditions using tetrabutylammonium fluoride trihydrate in dichloromethane thus allowing the construction of complex molecules sensitive to basic and acidic media commonly required for the cleavage of standard linker systems. The advantages of the PTMSEL linker are demonstrated in the synthesis of glycopeptides from the liver intestine (LI)-cadherin and the mucin MUC1, bearing carbohydrate moieties such as N-linked chitobiose or O-linked sialyl-T(N)-residues. The synthesis of the…
Non-Planar and Flexible Hole-Transporting Materials from Bis-Xanthene and Bis-Thioxanthene Units for Perovskite Solar Cells
2019
Two new hole-transporting materials (HTMs), BX-OMeTAD and BTX-OMeTAD, based on xanthene and thioxanthene units, respectively, and bearing p-methoxydiphenylamine peripheral groups, are presented for their use in perovskite solar cells (PSCs). The novelty of the newly designed molecules relies on the use of a single carbon-carbon bond ‘C−C’ as a linker between the two functionalized heterocycles, which increases the flexibility of the molecule compared with the more rigid structure of the widely used HTM spiro-OMeTAD. The new HTMs display a limited absorbance in the visible region, due to the lack of conjugation between the two molecular halves, and the chemical design used has a remarkably i…
Structure-immunogenicity relationship of kresoxim-methyl regioisomeric haptens
2013
Kresoxim-methyl was one of the two first strobilurins to be discovered, and nowadays it is widely used as an antifungal agent in crop protection. Because of its low molecular weight and negligible structural complexity, the generation of antibodies to kresoxim-methyl noticeably requires the preparation of functionalized haptens. In this study, the introduction of a hydrocarbon spacer arm at the aromatic moieties of the target molecule was carried out by a convergent strategy based on the Sonogashira cross-coupling reaction, and functionalized linkers of the same length were also tethered to the aliphatic toxophore group by the O-alkylation reaction. Evaluation of the immune response, in ter…
Synthetic Glycopeptides for the Development of Antitumour Vaccines
2003
Glycoproteins of tumour cells often are aberrantly glycosylated. In its tumour-associated form, the epithelial mucin MUC1 carries short saccharide structures such as TN, T, sialyl-TN, and sialyl-T antigens. Due to the incomplete saccharide components, peptide epitopes of the backbone become accessible to the immune system. For the construction of synthetic antitumour vaccines, glycopeptides have been synthesized which contain tumour-associated saccharide antigens and peptide sequences from the tandem repeat portion of MUC1. In the synthesis of these glycopeptides, preformed glycosyl–amino acid building blocks are applied in solution- or solid-phase strategies. Examples are given for the use…
Aqueous self-assembly and cation selectivity of cobaltabisdicarbollide dianionic dumbbells.
2014
The anion [3,3'-Co(C2B9H11)2](-) ([COSAN](-)) produces aggregates in water. These aggregates are interpreted to be the result of C-H⋅⋅⋅H-B interactions. It is possible to generate aggregates even after the incorporation of additional functional groups into the [COSAN](-) units. The approach is to join two [COSAN](-) anions by a linker that can adapt itself to act as a crown ether. The linker has been chosen to have six oxygen atoms, which is the ideal number for K(+) selectivity in crown ethers. The linker binds the alkaline metal ions with different affinities; thus showing a distinct degree of selectivity. The highest affinity is shown towards K(+) from a mixture containing Li(+), Na(+), …
Carbamate Linker Strategy in Solid-Phase Synthesis of Amino-Functionalized Glycoconjugates for Attachment to Solid Surfaces and Investigation of Prot…
2009
Amino-functionalized serine-based galactose and glucose neoglycolipids were prepared by solid-phase synthesis using a carbamate strategy for anchoring amino functionalities to a (2-fluoro-4-hydroxy ...