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Synthetic Protein (synthetic + protein)

Distribution by Scientific Domains

Chemistry	80%

Selected Abstracts

Biotec Visions 2010, May,June

BIOTECHNOLOGY JOURNAL, Issue 5 2010
Article first published online: 3 MAY 2010
News:Ethanol biofuels from orange peels , Targeting leukaemia's gene addiction , Pea-derived solar cells , HIV is a kick in the head , Nano-scale DNA reader , Membrane in black , Cheese improves the immune response of elderly , Synthetic proteins built from standard parts , Therapeutic proteins produced in algae , Biosensor detects 100 mycoplasma cells , Protecting maggots against bacteria , Advanced biofuels from microbes , Fluorescent bacterial uptake , Two disparate stem cell states , Brachypodium genome sequenced Encyclopedia of Life Sciences: Nuclear transfer for cell lines WIREs Nanomedicine and Nanobiotechnology: Nanoparticle detection of respiratory infection Journal Highlights: Biocatalysis , Synthetic Biology In the news: Nanobiotech to detect cancer Most Read Industry News: Biomarker assays for personalized medicine , Bioplastic industry defies economic crisis , SDS-PAGE monitoring of mAB Awards: BTJ Editors elected members of the US National Academy of Engineering (NAE) Meeting highlight Writing tips: Figure preparation made simple , Some useful tutorials on the web Book Highlights:Molecular Biotechnology , Bacterial Signaling , Yeast Test your knowledge:Do you recognize this? WIREs Authors Spotlight:Nanotechnology and orthopedics [source]

Design, synthesis, and characterization of a novel hemoprotein

PROTEIN SCIENCE, Issue 2 2001
Zhijin Xu
Abstract Here we describe a synthetic protein (6H7H) designed to bind four heme groups via bis,histidine axial ligation. The hemes are designed to bind perpendicular to another in an orientation that mimics the relative geometry of the two heme a groups in the active site of cytochrome c oxidase. Our newly developed protein-design program, called CORE, was implemented in the design of this novel hemoprotein. Heme titration studies resolved four distinct KD values (KD1 = 80 nM, KD2 = 18 nM, KD3 , 3 mM, KD4 , 570 nM, with KD3 × K D4 = 1700); positive cooperativity in binding between the first and second heme, as well as substantial positive cooperativity between the third and forth heme, was observed. Chemical and thermal denaturation studies reveal a stable protein with native-like properties. Visible circular dichroism spectroscopy of holo-6H7H indicates excitonic coupling between heme groups. Further electrochemical and spectroscopic characterization of the holo-protein support a structure that is consistent with the predefined target structure. [source]

A Designed Well-Folded Monomeric Four-Helix Bundle Protein Prepared by Fmoc Solid-Phase Peptide Synthesis and Native Chemical Ligation,

CHEMISTRY - A EUROPEAN JOURNAL, Issue 5 2006
Gunnar T. Dolphin Dr.
Abstract The design and total chemical synthesis of a monomeric native-like four-helix bundle protein is presented. The designed protein, GTD-Lig, consists of 90 amino acids and is based on the dimeric structure of the de novo designed helix-loop-helix GTD-43. GTD-Lig was prepared by the native chemical ligation strategy and the fragments (45 residues long) were synthesized by applying standard fluorenylmethoxycarbonyl (Fmoc) chemistry. The required peptide,thioester fragment was prepared by anchoring the free ,-carboxy group of Fmoc-Glu-allyl to the solid phase. After chain elongation the allyl moiety was orthogonally removed and the resulting carboxy group was functionalized with a glycine,thioester followed by standard trifluoroacetic acid (TFA) cleavage to produce the unprotected peptide,thioester. The structure of the synthetic protein was examined by far- and near-UV circular dichroism (CD), sedimentation equilibrium ultracentrifugation, and NMR and fluorescence spectroscopy. The spectroscopic methods show a highly helical and native-like monomeric protein consistent with the design. Heat-induced unfolding was studied by tryptophan absorbance and far-UV CD. The thermal unfolding of GTD-Lig occurs in two steps; a cooperative transition from the native state to an intermediate state and thereafter by noncooperative melting to the unfolded state. The intermediate exhibits the properties of a molten globule such as a retained native secondary structure and a compact hydrophobic core. The thermodynamics of GuHCl-induced unfolding were evaluated by far-UV CD monitoring and the unfolding exhibited a cooperative transition that is well-fitted by a two-state mechanism from the native to the unfolded state. GTD-Lig clearly shows the characteristics of a native protein with a well-defined structure and typical unfolding transitions. The design and synthesis presented herein is of general applicability for the construction of large monomeric proteins. [source]

Channel properties of template assembled alamethicin tetramers,

JOURNAL OF PEPTIDE SCIENCE, Issue 11-12 2003
Dr Hervé Duclohier
Abstract The multiple conductance levels displayed by the antibiotic alamethicin in planar lipid bilayers is explained by a dynamic ,barrel-stave' model, the conducting pore resulting from the aggregation of up to ten helical amphipathic helical monomers. However, the precise assignment of an oligomerization state to a particular single-channel conductance substate is far from being experimentally clear. In addition, it could be useful to tailor a given channel geometry to selectively allow the permeation of solutes with different molecular sizes, whilst retaining a high voltage-dependence. To control the aggregation state of the channel, the TASP (template assembled synthetic proteins) strategy was applied to synthesize structurally defined oligomers, i.e. dimer, trimer, tetramer. The modulation of conductance properties of three alamethicin tetramers with the length and flexibility of the linkers of the ,open' or linear template is described. It is shown that the introduction of an alanine between the contiguous lysines to which are tethered C -terminally modified alamethicin helical monomers stabilizes the open channel states, whereas the alanine substitution by Pro-Gly, a reverse beta-turn promoting motif, increases voltage-dependence and leads to single-channel conductance values more in line with the expected ones from a tetrameric bundle. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd. [source]

Chemical Synthesis of Triple-Labelled Three-Helix Bundle Binding Proteins for Specific Fluorescent Detection of Unlabelled Protein

CHEMBIOCHEM, Issue 6 2005
Torun Engfeldt
Abstract Site-specifically triple-labelled three-helix bundle affinity proteins (affibody molecules) have been produced by total chemical synthesis. The 58 aa affinity proteins were assembled on an automated peptide synthesizer, followed by manual on-resin incorporation of three different reporter groups. An orthogonal protection strategy was developed for the site-specific introduction of 5-(2-aminethylamino)-1-naphthalenesulfonic acid (EDANS) and 6-(7-nitrobenzofurazan-4-ylamino)-hexanoic acid (NBDX), constituting a donor/acceptor pair for fluorescence resonance energy transfer (FRET), and a biotin moiety, used for surface immobilization. Circular dichroism and biosensor studies of the synthetic proteins and their recombinant counterparts revealed that the synthetic proteins were folded and retained their binding specificities. The biotin-conjugated protein could be immobilized onto a streptavidin surface without loss of activity. The synthetic, doubly fluorescent-labelled affinity proteins were shown to function as fluorescent biosensors in an assay for the specific detection of unlabelled human IgG and IgA. [source]