Protein engineering

This project is focused on studying the biological effects of low-power RF radiation on the expression and function of mechanosensitive ion channel protein (Piezo-1). To evaluate the effects of long-term exposures, cells were exposed at the frequency of 1800 MHz and power of 17 dBm for a period of 2 and 4 hrs using the transverse electromagnetic (TEM) cell exposure system. To study the effects of short-term RF radiation (10 min), exposures emitted from the mobile phone headset at the frequency of 845 MHz and powers of -15 dBm and -5 dBm were applied to cell cultures.

141p runthenight04 02-02-2023 14 3   Download

Division of Medicinal and Natural Products Chemistry, Department of Chemistry and Department of Chemical Engineering, University of Iowa, USA; 2Department of Autoimmunology, Statens Serum Institut, Copenhagen, Denmark Synthetic peptides based on amino-acid residues 27–38 of human serum amyloid P component represent a novel type of heparin binders as they do not contain clusters of basic amino acids or other known features associated with protein or peptide heparin binding.

8p system191 01-06-2013 56 4   Download

Affinity reagents capable of selective recognition of the different human immunoglobulin isotypes are important detection and purification tools in biotechnology. Here we describe the development and characterization of affinity proteins (affibodies) showing selective binding to human IgA. From protein libraries constructed by combinatorial mutagenesis of a 58-amino-acid, three-helix bundle domain derived from the IgG-binding staphylococcal protein A, variants showing IgA binding were selected by using phage display technology and IgA monoclonal antibodies (myeloma) as target molecules. ...

9p system191 01-06-2013 39 3   Download

Cytochrome c is widely distributed in bacterial species, from mesophiles to thermophiles, and is one of the best-characterized redox proteins in terms of biogenesis, folding, structure, function, and evolution. Experimental molecular biology techniques (gene cloning and expression) have become applicable to cytochrome c, enabling its engineering and manipulation. Heterologous expression systems for cytochromes c in bacteria, for use in mutagenesis studies, have been established by extensive investigation of the biological process by which the functional structure is formed. ...

7p research12 01-06-2013 36 3   Download

The aim of this study was to increase the stability of the thermolabile (ba)8-barrel enzyme indoleglycerol phosphate synthase from Escherichia coli by the introduction of disulfide bridges. For the design of such variants, we selected two out of 12 candidates, in which newly introduced cysteines potentially form optimal disulfide bonds. These variants avoid short-range connections, substitutions near catalytic residues, and crosslinks between the new and the three parental cysteines.

9p research12 01-06-2013 41 4   Download

Fibritin is a segmented coiled-coil homotrimer of the 486-residue product of phage T4 gene wac. This protein attaches to a phage particle by the N-terminal region and ˚ forms fibrous whiskers of 530 A, which perform a chaperone function during virus assembly. The short C-terminal region has a b-annulus-like structure. We engineered a set of fibritin deletion mutants sequentially truncated from the N-termini, and the mutants were studied by differential scanning calorimetry (DSC) and CD measurements....

9p research12 01-06-2013 44 3   Download

The envelope protein gp64 of the baculovirusAutographa californicanuclear polyhedrosis virus is essential for viral entry into insect cells, as the glycoprotein bothmediates pH-dependentmembrane fusionandbinds tohost cell receptors. Surface modification of baculovirus particles by genetic engineering of gp64 has been demonstrated by various strategies and thus has become an important and powerful tool in molecular biology.

10p research12 23-04-2013 28 2   Download

Staphylokinase (SAK) is a 15.5-kDa protein fromStaphy-lococcus aureusthat activates plasminogenby forminga1 : 1 complex with plasmin. Recombinant SAK has been shown in clinical trials to induce ®brin-speci®c clot lysis in patients withacutemyocardial infarction.However, SAKelicits high titers of neutralizing antibodies. Biochemical and protein engineering studies have demonstrated the feasibility of generatingSAKvariantswith reducedantigenicity yet intact thrombolytic potency.

7p research12 23-04-2013 43 3   Download

The solution structure of three small serine proteinase inhibitors, two natural and one engineered protein, SGCI (Schistocerca gregaria chymotrypsin inhibitor), SGCI[L30R, K31M] and SGTI (Schistocerca gregaria trypsin inhibitor), were determined by homonuclear NMR-spectroscopy. The molecules exhibit di€erent speci®cities towards target proteinases, where SGCI is a good chymo-trypsin inhibitor, itsmutant is apotent trypsin inhibitor, and SGTI inhibits both proteinases weakly.

11p research12 23-04-2013 35 2   Download

Engineered yeast cells efficiently convert ergosta-5-eneol to pregnenolone and progesterone provided that endogenous pregnenolone acetylase activity is disrupted and that heterologous sterolD7-reductase, cytochrome P450 side chain cleavage (CYP11A1) and 3b hydroxysteroid dehydrogenase/isomerase (3b-HSD) activities are present. CYP11A1activity requires the expressionof themammalian NADPH-adrenodoxin reductase (Adrp) and adrenodoxin (Adxp) proteins as electron carriers.

13p tumor12 20-04-2013 29 2   Download

Microorganisms produce a large number of pharmaco-logically and biotechnologically important peptides by using nonribosomal peptide synthetases (NRPSs). Due to their modular arrangement and their domain organization NRPSs are particularly suitable for engineering recom-binant proteins for the production of novel peptides with interesting properties.

9p fptmusic 12-04-2013 62 3   Download

The development of targeted probes (based on the molecular engineering of luminescent or fluorescent proteins) has allowed the specific measure-ment of [Ca 2+ ] in intracellular organelles or cytoplasmic subdomains. This approach gave novel information on different aspects of cellular Ca 2+ homeostasis. Regarding mitochondria, it was possible to demonstrate that, upon physiological stimulation of cells, Ca 2+ is rapidly accumulated in the matrix.

10p fptmusic 11-04-2013 41 2   Download

A bio-nanocapsule (BNC), composed of the surface antigen (sAg) of the hepatitis B virus, is an efficient nanomachine with which to accomplish the liver-specific delivery of genes and drugs. Approximately 110 molecules of sAg are associated to form a BNC particle with an average diameter of 130 nm. TheLprotein is an sAg peptide composed mainly of preS and S regions. The preS region, with specific affinity for human hepatocytes, is localized in the N-terminus.

10p fptmusic 11-04-2013 37 2   Download

Limited proteolysis in combination with liquid chromatography-ion trap mass spectrometry (LC-MS) was used to analyze engineered or natural proteins derived from a type I modular polyketide synthase (PKS), the 6-deoxyerythronolide B synthase (DEBS), and comprising either the first two extension modules linked to the chain-terminating thioesterase (TE) (DEBS1-TE); or the last two extension modules (DEBS3) or the first exten-sion module linked to TE (diketide synthase, DKS).

15p awards 06-04-2013 38 1   Download

NA helicases are ubiquitous molecular motor proteins which harness the chemical free energy of ATPhydrolysis to catalyze the unwinding of energetically stable duplex DNA, and thus play important roles in nearly all aspects of nucleic acid metabolism, including replication, repair, recombina-tion, and transcription. They break the hydrogen bonds between the duplex helix and move unidirectionally along the bound strand. All helicases are also translocases and DNA-dependentATPases.Most contain conserved helicase motifs that act as an engine to power DNA unwinding. ...

14p dell39 03-04-2013 38 5   Download

Pyruvate carboxylase (PC) fromBacillus thermodenitrificans was engineered in such away that the polypeptide chainwas divided into two, between the biotin carboxylase (BC) and carboxyl transferase (CT) domains. The two proteins thus formed, PC-(BC) and PC-(CT+BCCP), retained their catalytic activity as assayed by biotin-dependent ATPase and oxamate-dependent oxalacetate decarboxylation, for the former and the latter, respectively. Neither activity was dependent on acetyl-CoA, in sharp contrast to the complete reaction of intact PC. ...

10p dell39 03-04-2013 41 5   Download

We have engineered a stable octameric hemoglobin (Hb) of molecular mass 129 kDa, a dimer of recombinant hemoglobin (rHbbG83C-F41Y) tetra-mers joined by disulfide bonds at theb83 position. One of the major prob-lems with oxygen carriers based on acellular hemoglobin solutions is vasoactivity, a limitation which may be overcome by increasing the mole-cular size of the carrier.

12p dell39 27-03-2013 40 2   Download

Molecular identification of adrenal inner zone antigen as a heme-binding protein Li Min1*, Natallia V. Strushkevich1,2*, Ivan N. Harnastai2, Hiroko Iwamoto3, Andrei A. Gilep1,2, Hiroshi Takemori1, Sergey A. Usanov2, Yasuki Nonaka3, Hiroshi Hori4, Gavin P.

12p dell39 27-03-2013 54 6   Download

Cell-free translation systems have developed significantly over the last two decades and improvements in yield have resulted in their use for protein production in the laboratory. These systems have protein engineering appli-cations, such as the production of proteins containing unnatural amino acids and development of proteins exhibiting novel functions.

8p inspiron33 25-03-2013 42 6   Download

We show a simple and reliable method of tRNA aminoacylation with natural, as well as non-natural, amino acids at high pressure. Such specific and noncognate tRNAs can be used as valuable substrates for protein engineering. Aminoacylation yield at high pressure depends on the chem-ical nature of the amino acid used and it is up to 10%.

10p inspiron33 25-03-2013 46 3   Download