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Artificial Proteins (artificial + protein)

Distribution by Scientific Domains

Polymers and Materials Science	60%
Chemistry	40%

Selected Abstracts

Effect of Motif-Programmed Artificial Proteins on the Calcium Uptake in a Synthetic Hydrogel

MACROMOLECULAR BIOSCIENCE, Issue 10 2009
Traian V. Chirila
Abstract Motif-programmed artificial proteins with mineralization-related activity were covalently immobilized onto the surface of a hydrogel, poly(2-hydroxyethyl methacrylate) (PHEMA). We investigated the influence of assaying conditions upon the ability of three selected proteins (PS64, PS382 and PS458) to modulate calcification in vitro. A long-term assay measuring the real amount of calcium phosphate phase in the protein-modified PHEMA showed that all proteins enhanced the uptake of calcium by the hydrogel. For PS382 and PS458, this is a behaviour opposite to that displayed when the same proteins were tested in a free state by a rapid solution assay. Such difference may be attributed to a restricted mobility of the proteins due to immobilization. [source]

Computational design of proteins stereochemically optimized in size, stability, and folding speed

BIOPOLYMERS, Issue 2 2006
Sadhna Joshi
Abstract Artificial proteins potentially barrier-free in the folding kinetics are approached computationally under the guidance of protein-folding theories. The smallest and fastest folding globular protein triple-helix-bundle (THB) is so modified as to minimize or eliminate its presumed barriers in folding speed. As the barriers may reside in the ordering of either secondary or tertiary structure, the elements of both secondary and tertiary structure in the protein are targeted for prenucleation with suitable stereochemically constrained amino acid residues. The required elements of topology and sequence for the THB are optimized independently; first the topology is optimized with simulated annealing in polypeptides of highly simplified alphabet; next, the sequence in side chains is optimized using the standard inverse design methods. The resultant three best-adapted THBs, variable in topology and distinctive in sequences, are assessed by comparing them with a few benchmark proteins. The results of mainly molecular dynamics (MD) comparisons, undertaken in explicit water at different temperatures, show that the designed sequences are favorably placed against the chosen benchmarks as THB proteins potentially thermostable in the native folds. Folding simulation experiments with MD establish that the designed sequences are rapid in the folding of individual helices, but not in the evolution of tertiary structure; energetic cum topological frustrations remain but could be the artifacts of the starting conformations that were chosen in the THBs in the folding simulations. Overall, a practical high-throughput approach for de novo protein design has been developed that may have fruitful application for any type of tertiary structure. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 122,134, 2006 This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source]

Synthesis of new S -glycodendrimer toward activation of lac operon transcription for protein biosynthesis

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 1 2009
Akinori Takasu
To enable gene transcription or lac operon transcription, isopropyl ,- D -thiogalactoside (IPTG) and allolactose can bind to the lac repressor. New S -glycodendrimers for activation of the lac operon were synthesized by S -glycosidation and DCC-HOBt coupling with a poly(amidoamine) dendrimer. Expression of artificial protein was performed for Escherichia coli using these glycodendrimers as the inducers. Cells encoded with green fluorescent protein (GFP) were induced with the glycoconjugates. After expression at 37 °C for 4 h, fluorescence emissions were actually observed through visual observation, which indicated that S -glycodendrimer acted as an inducer for protein biosynthesis. Quantitative analysis using fluorescence spectrometer was carried out to evaluate the activity. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.] [source]

Effect of Motif-Programmed Artificial Proteins on the Calcium Uptake in a Synthetic Hydrogel

Thermally associating polypeptides designed for drug delivery produced by genetically engineered cells

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2007
David S. Hart
Abstract Thermally associating polymers, including gelatin, cellulose ethers (e.g., Methocels® and poloxamers (e.g., Pluronics®) have a long history of use in pharmacy. Over the past 20 years, significant advances in genetic engineering and the understanding of protein secondary and tertiary structures have been made. This has led to the development of a variety of polypeptides that do not occur naturally but can be expressed in recombinant cells and have useful properties that lend themselves to novel applications where current materials cannot perform. The most intensively studied motifs are derived from the consensus repeats of elastin and silk, as well as coiled-coil helices. Many of these designed polypeptides or ,artificial proteins' are thermally associating materials. This property can be exploited to develop solid dosage forms, injectable drug delivery systems, micro- or nanoparticle drug carriers, triggered or targeted release systems, or as a means of simplifying the purification process and thus reducing costs of production of these materials. This review focuses on the development and characterization of this novel class of biomaterials and examines their potential for pharmaceutical applications. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci [source]