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Search for "amino acid" in Full Text gives 82 result(s) in Beilstein Journal of Nanotechnology.
L-Lysine-grafted graphene oxide as an effective adsorbent for the removal of methylene blue and metal ions
Beilstein J. Nanotechnol. 2017, 8, 2680–2688, doi:10.3762/bjnano.8.268
- because more functional groups are available. 2) Strong π–π interactions and vacancy defects are good for enhancing the adsorption capacity of graphene materials. These results indicated that Lys-GO material has great potential application in treating wastewater. Conclusion A novel amino acid–graphene
Strategy to discover full-length amyloid-beta peptide ligands using high-efficiency microarray technology
Beilstein J. Nanotechnol. 2017, 8, 2446–2453, doi:10.3762/bjnano.8.243
- mid-1990’s presented the KLVFF pentapeptide (Aβ16–20) as a strategy to arrest the formation of β-amyloid fibrils, confirming that amino-acid residues located within or close to this region are important for the adoption of the correct β-sheet structure of Aβ [30]. Semax is an hexapeptide (Met–Glu–His
- ribbon aggregates are clearly visible. Propensity of the epoxysilane HESs to immobilize peptides Silanization has been widely-used as a strategy to prepare optimal protein or DNA microarrays [25][26][40], the epoxide groups may bind peptide molecules through the reaction with the basic amino acid
Self-assembly of chiral fluorescent nanoparticles based on water-soluble L-tryptophan derivatives of p-tert-butylthiacalix[4]arene
Beilstein J. Nanotechnol. 2017, 8, 1825–1835, doi:10.3762/bjnano.8.184
- with bromoacetyl bromide carried out in benzene at room temperature according to the literature procedure [39] (Scheme 1). The alkylating reagent 3 was chosen owing to the presence of aromatic fragments in the structure of the chiral amino acid. The ammonium derivatives of thiacalix[4]arene can form
- self-associates not only due to hydrogen bonds, but also due to π–π-stacking and the hydrophobic effects of the chiral amino acid with aromatic fragments [40]. The presence of amide fragments in the structure of the resulting macrocycles also contributes to the formation of aggregates via self
- aggregates formed by the p-tert-butylthiacalix[4]arenes 8–11 containing amide, quaternary ammonium and amino acid fragments in cone and 1,3-alternate conformation were also investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) (Figure 2, Supporting Information File 1
Methionine-mediated synthesis of magnetic nanoparticles and functionalization with gold quantum dots for theranostic applications
Beilstein J. Nanotechnol. 2017, 8, 1734–1741, doi:10.3762/bjnano.8.174
- magnetic NPs with gold quantum dots (QDs) containing more than 13.5% of Au+. Emphasis is put on the synthesis of magnetic NPs by co-precipitation using the amino acid methionine as NP growth-stabilizing agent capable to later reduce and attach gold species. The surface of these NPs can be further
- has been previously reported, such frequency downshift is due to the direct interaction of the carboxylate group of the amino acid with the NP surface [43]. We also suspect that the appearance of the significantly stronger symmetric vibration mode in the FTIR spectrum of gold decorated NPs at 1515 cm
Recombinant DNA technology and click chemistry: a powerful combination for generating a hybrid elastin-like-statherin hydrogel to control calcium phosphate mineralization
Beilstein J. Nanotechnol. 2017, 8, 772–783, doi:10.3762/bjnano.8.80
- polymers (ELPs) or recombinamers (ELRs), which are excellent example of materials that exhibit self-assembly and self-organization [27][28][29]. The majority of ELPs or ELRs consist of simple amino-acid consensus epitopes that are also present in natural elastin, such as (VPGXG)* (see Table 1 for details
- of sample nomenclature), where the guest amino acid X can be any of the natural or synthetic L-amino acids except L-proline. ELRs exhibit an intrinsic inverse temperature transition (Tt) in aqueous solution. Thus, below Tt, the ELR chains are highly hydrated, which gives rise to well-solvated
- polymers in a random coil conformation, whereas above Tt, the ELR chains self-assemble into β-turns, which are organized into a fibrillar morphology [27][30]. Changes to the guest residue X modulate Tt, with the key influence being the polarity of the amino acid side-chain in X. As such, ELRs can be
Comparison of four functionalization methods of gold nanoparticles for enhancing the enzyme-linked immunosorbent assay (ELISA)
Beilstein J. Nanotechnol. 2017, 8, 244–253, doi:10.3762/bjnano.8.27
- of free amine groups (few lysine amino acid residues) compared to the antibody molecule. The lower availability of free amino groups could hamper the attachment of peroxidase in the covalent strategy (Figure 1c), although more experiments should be performed to confirm this. Consequently, this would
Controlled supramolecular structure of guanosine monophosphate in the interlayer space of layered double hydroxide
Beilstein J. Nanotechnol. 2016, 7, 1928–1935, doi:10.3762/bjnano.7.184
- ancient environment, many scientists have begun to focus their research on the molecular arrangement of biological substances in the interlayer space of layered inorganics [3][4]. In those investigations, monomeric prebiotic molecules such as amino acid, nucleoside or nucleotide were intercalated and it
3D printing of mineral–polymer bone substitutes based on sodium alginate and calcium phosphate
Beilstein J. Nanotechnol. 2016, 7, 1794–1799, doi:10.3762/bjnano.7.172
- , correspondently, amino acid concentration increases from 0.25 to 2.0 wt % (Figure 2). The FTIR spectra of DCPD exhibits principal characteristic bands known to be associated with РО4 (ν4) at 575 and 1125 cm−1, (ν1) at 981 cm−1, (ν3) at 870 cm−1 and 1056 cm−1; as well as H2O at 650 cm−1, 790 cm−1 [15]. In our FTIR
Effective intercalation of zein into Na-montmorillonite: role of the protein components and use of the developed biointerfaces
Beilstein J. Nanotechnol. 2016, 7, 1772–1782, doi:10.3762/bjnano.7.170
- detergents [16][18][19]. The solubility is attributed to the non-polar amino acid residues of the protein, such as valine, leucine, proline, isoleucine, alanine, and phenylalanine, which confer a hydrophobic character to the protein [16]. Therefore, a good knowledge of structural and solubility properties of
- signals between 173–175 ppm due to carbonyls present in the peptide groups in both the main chain and the protein side chains. The signals at 128 ppm, those from 45 to 70 and those from 15 to 45 ppm are assigned to amino acid aromatic side chains, α-carbons linked to amino groups, and carbons from the
- amino acid aliphatic side chains, respectively [33]. Thus, these studies indicate that although zein cannot be dissolved in pure ethanol, a separation process of different components of the protein occurs in this medium corresponding to the soluble (EXT) and insoluble zein fractions (PCT), where EXT
Preparation of alginate–chitosan–cyclodextrin micro- and nanoparticles loaded with anti-tuberculosis compounds
Beilstein J. Nanotechnol. 2016, 7, 1208–1218, doi:10.3762/bjnano.7.112
- interactions were predicted between the isoconazole and sulfur-containing methionine amino acid residues of InhA (Met98, Met103, and Met199). Also an arene–H interaction was obtained between the imidazole ring of isoconazole and NAD+ cofactor. The catalytic residues of InhA Tyr158 and Thr196 provided polar
- Figure 13a, the electron density of the HOMO was distributed on the atoms of the amino acid residues. Methionine amino acids and Ile215, Tyr158, Gly96, and Phe97 residues are involved in the acceptor interaction of the HOMO. In contrast, the role of frontier orbitals in the ligand–receptor interaction
- was significant for the LUMO (Figure 13b). Atoms of both isoconazole and amino acid residues (Met199, Thr196, Ala198, Ile202, Met161, and Tyr158) contributed to the donor–acceptor interaction. Conclusion The obtained microparticulate and nanoparticulate systems of alginate–chitosan–β-cyclodextrin with
Unraveling the neurotoxicity of titanium dioxide nanoparticles: focusing on molecular mechanisms
Beilstein J. Nanotechnol. 2016, 7, 645–654, doi:10.3762/bjnano.7.57
- affected by DNA methylation. DNA methylation was associated with expression of neurotransmitters. In an in vitro study, hypermethylation of the excitatory amino acid transporter (EAAT2) promoter in glioma cells led to a deficiency in astroglial EAAT2 expression, which was related to the pathogenesis of CNS
Novel roles for well-known players: from tobacco mosaic virus pests to enzymatically active assemblies
Beilstein J. Nanotechnol. 2016, 7, 613–629, doi:10.3762/bjnano.7.54
- presentation of multiple active molecules or synthetic compounds. Amino acid side chains exposed on the viral coat may be tailored genetically or biochemically to meet the demands for selective conjugation reactions, or to directly engineer novel functionality on TMV-derived nanosticks. The natural TMV size
- different modes going on (see [29][30][31][32] for original research or for extensive reviews [33][34][35][36]). Concomitantly, infectivity and genetic organization of the viral RNA as well as the CP amino acid sequence were determined as reviewed in detail [37], with the complete RNA sequence published in
- 1982 [38]. Summing up, TMV was the first plant virus of which a highly resolved particle structure including the amino acid sequence of its protein, and all major gene functions had been unraveled. Furthermore, it was the first of all viruses with both assembly and disassembly shown to take place in
Bacteriorhodopsin–ZnO hybrid as a potential sensing element for low-temperature detection of ethanol vapour
Beilstein J. Nanotechnol. 2016, 7, 501–510, doi:10.3762/bjnano.7.44
- (at 1540 cm−1) due to N–H in-plane bending, which reflects the secondary structure of the protein (β-structure) [70][71][72]. Higher frequencies at 3070, 2950, 2920 and 2850 cm−1 are attributed to the alkyl C–H stretching vibration of both lipid and protein amino acid [63][65][73]. The gas sensing
Green and energy-efficient methods for the production of metallic nanoparticles
Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243
- Ag NPs were 21 and 39 nm respectively [38]. Carboxylic acids Lai et al. produced superparamagnetic Fe3O4 NPs from FeCl3 using a mixture of water and glycerol as solvent and L-arginine as stabilizing agent. L-arginine is an amino acid that is naturally produced and therefore it is considered to be a
- Ag ions during process [66]. Kumar et al. used amino acid based phenolic compounds as reducer and stabilizer for production of Ag NPs from AgNO3 at room temperature. They stated that amino acids have reactive hydroxyl groups and their structural variations can result in the production of spherical
Peptide-equipped tobacco mosaic virus templates for selective and controllable biomineral deposition
Beilstein J. Nanotechnol. 2015, 6, 1399–1412, doi:10.3762/bjnano.6.145
- outer TMV–CP surface charge and the introduction of specific amino acid motifs, guiding the nucleation and growth of mineral coatings around the TMV core. This is in analogy to natural biomineralization-directing protein domains identified for various organisms [55][56][57][58][59]. Direct genetic
- conjugation of synthetic peptides meant to regulate subsequent coating with silica (workflow indicated in Figure 1). This procedure is insensitive to both size and sequence of the peptide of choice, and the generation of various types of decorated TMV rods is fast. The amino acid sequences employed had been
- the silica mineralization can be achieved by ordered, repetitive arrangements of differently charged protein domains and specific functional groups therein. This was demonstrated in vitro by help of various mineralization-inducing peptides [55][56][61][72]. Positively charged amino acid residues (Lys
Natural and artificial binders of polyriboadenylic acid and their effect on RNA structure
Beilstein J. Nanotechnol. 2015, 6, 1338–1347, doi:10.3762/bjnano.6.138
- molecules but also by interaction with nucleopeptides, metal–amino acid complexes, nanotubes, etc. Indeed, from a structural point of view, numerous studies were conducted in the last forty years describing in detail the properties of poly(rA) and its complexes with various molecules, such as DNA
- glucosides; others are artificial, as in the case of proflavine, 4',6-diamidino-2-phenylindole dihydrochloride (DAPI), azacyanines, nucleopeptides, benzodifurans, nanotubes and metal–amino acid complexes. Poly(rA) binders of natural origin and their synthetic derivatives Alkaloids Isoquinoline alkaloids
- the absence of this poly(rA) ligand is stable only in acidic conditions. Amino acid–metal complexes Another original example of a poly(rA) binding system different from alkaloids or other small organic molecules can be found in the research work of Zhang et al. [65], where the effects on nucleic acid
Release behaviour and toxicity evaluation of levodopa from carboxylated single-walled carbon nanotubes
Beilstein J. Nanotechnol. 2015, 6, 243–253, doi:10.3762/bjnano.6.23
- -(3,4-dihydroxyphenyl)propanoic acid (levodopa) still remains the gold standard for the treatment of PD for symptomatic relief [12]. Now entering into its fourth decade of clinical use, levodopa (LD, the amino acid precursor of dopamine) is the most effective, widely prescribed, oral administered drug
Functionalization of α-synuclein fibrils
Beilstein J. Nanotechnol. 2015, 6, 124–133, doi:10.3762/bjnano.6.12
- including Parkinson’s disease [8][9], was chosen as a building block element. α-Syn is a small 140 amino acid long protein that is highly soluble and heat-stable. Three regions can be recognized in α-Syn: a highly conservative N-terminal region, a variable internal non-amyloid component (NAC) (which is
- any preformed aggregates [14][19] and mutations in the amino acid sequence of the protein [20]. From a medical point of view, the aggregation of proteins including α-Syn is unfavourable in vivo, yet, amyloid fibrils have a potential to be engineered into novel, proteinous, nanoscale materials and
- was constructed as described in the Experimental section. After expression in E. coli BL21 (DE3) cells, α-SynC141 was found as a soluble protein and the level of expression was the same as that of a native α-Syn. The presence of the additional amino acid in the C-terminus did not affect the solubility
Chemoselective silicification of synthetic peptides and polyamines
Beilstein J. Nanotechnol. 2015, 6, 103–110, doi:10.3762/bjnano.6.10
- analyzed to what extent the mineralisation process and the morphology of the precipitate depends on the number of propyleneimino repeating units [11], the type of KXXK-boxes in silaffin proteins (K = Lys, X = other amino acid) [12], or the number of POG tripeptide repeating units in collagens [13]. The
- amine remains reactive for peptide coupling. The HBTU/HOBt-mediated condensation of a Fmoc-acylated amino acid and cleavage of the temporary protecting group Fmoc with piperidine was repeated in 15 cycles to obtain CTC-bound precursor of peptide 5 which was finally Boc-deprotected by TFA and
Synthesis of boron nitride nanotubes and their applications
Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9
- investigation concerning the interactions of BNNTs with tryptophan (Trp), aspartic acid (Asp), and arginine (Arg) was also carried out [68]. It was found that the polar Asp and Arg interacted with the BNNT surface through the charge transfer and electrostatic interactions while Trp, a neutral amino acid, had no
Liquid-phase exfoliated graphene: functionalization, characterization, and applications
Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242
- cycloaddition, performed on graphene by employing an aldehyde and an α-amino acid as precursors, attacks both graphene faces and edges. This reactivity was observed by introducing protonated terminal amino groups that selectively bind gold nanorods allowing the recognition of the reactive sites by low
Biopolymer colloids for controlling and templating inorganic synthesis
Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222
- 2) [38]. In a more recent work, we have also shown that charged acidic peptides are able to stabilize vaterite, and we studied the effect of the acidity of the amino acid residues on this stabilization [39]. In a previous work, synthetic polymer colloidal particles functionalized with different
Carbon nano-onions (multi-layer fullerenes): chemistry and applications
Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207
- heated with an amino acid and paraformaldehyde. Following filtration and washing with toluene, the solid was suspended in chloroform. After one week, the formed precipitate was removed and the functionalized CNO material was obtained by evaporation of the chloroform. The authors reported that the final
- solvents and give rise to potential future applications in various fields of technology. The synthesis of ferrocene (Fc)-decorated CNOs was reported by Prato et al. [34]. CNOs were functionalized in a 1,3-dipolar cycloaddition reaction with a BOC-protected amin/amino acid [35] and paraformaldehyde
PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments
Beilstein J. Nanotechnol. 2014, 5, 1944–1965, doi:10.3762/bjnano.5.205
- , the dissolution rate is strongly increased. On the other hand, the dissolution is significantly slower in the presence of dissolved NaCl, a fact that may be due to the formation of insoluble silver chloride. An even stronger inhibiting effect is exerted by the sulfur-containing amino acid cysteine. We
- . As an early response to genomic DSB, a variant of histone H2A becomes phosphorylated at amino acid 139 by members of the PI3-kinase family in the direct vicinity of the break. The phosphorylated form of H2AX (γ-H2AX) is necessary to activate the DSB-repair machinery [117] and therefore, it can be
Protein-coated pH-responsive gold nanoparticles: Microwave-assisted synthesis and surface charge-dependent anticancer activity
Beilstein J. Nanotechnol. 2014, 5, 1452–1462, doi:10.3762/bjnano.5.158
- and thereby deactivates some of the amino acid residues responsible for the reduction of the Au ions. Structural conformation The main objective of this work was the preparation of AuNPs by using proteins, not retaining the structural conformation of the proteins, because changes in the structural
- remaining proteins are expected to retain their amino acid sequence and not have extensive changes in their properties, such as their intrinsic pH and isoelectric points. Composition of amino acid residues Recent reports suggest that amino acid residues, such as aspartic acid, cysteine, glutamic acid
- , tyrosine and tryptophan, can reduce Au(III) and Ag(I) ions [12][18][38][41][42][43][44][45][46]. In this study, amino acid content of each protein is different due to differences in their molecular weights and amino acid sequences. Thus, predicting that a particular amino acid is responsible for the
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