Polymer protein

Mechanism of Dyeing. Wool (qv) is a complex protein polymer based on amino acid building blocks, and the polymer chains are cross-linked by disulfide groups. Amino acids (qv) contain both amino and carboxyUc acid groups and therefore the wool polymer contains both —NH2... 

The protein polymers are highly sterospecific, the aminoacid residues always adopting the L-configuration, i.e. the same configuration as the reference substance L-malic acid. 

CappeUo J. and Ferrari F., Microbial production of stmctural protein polymers, (Mobler D.P., ed.). Plastics from Microbes, Hanser PubUshers, Munich, 1994, 35. 

CappeUo J., Crissman J.W., Crissman M., Ferrari F.A., Textor G., WaUis O., Whitledge J.R., Zhou X., Butman D., Auketman L., and Stedronsky E.R. In-situ self-assembling protein polymer gel systems for administration, deUvety, and release of drugs, J. Contr. Rel., 53, 105, 1998. 

Gauthier MA, Klok HA (2008) Peptide/protein-polymer conjugates synthetic strategies and design concepts. Chem Commun 23 2591-2611... 

Top A, Kiick KL (2010) Multivalent protein polymers with controlled chemical and physical properties. Adv Drug Deliv Rev 62 1530-1540... 

Farmer RS, Kiick KL (2005) Conformational behavior of chemically reactive alanine-rich repetitive protein polymers. Biomacromolecules 6 1531-1539... 

Sallach RE, Cui W, Wen J et al (2009) Elastin-mimetic protein polymers capable of physical and chemical crosslinking. Biomaterials 30 409 22... 

Transcellular Transport of Protein—Polymer Conjugates in Cultured Epithelial Cells... 

SHEN ET AL. Transcellular Transport of Protein-Polymer Conjugates 119... 

SHEN ET AL. Transcelhdar Transport of Protein—Polymer Conjugates 121... 

Plants were probably the first to have polyester outerwear, as the aerial parts of higher plants are covered with a cuticle whose structural component is a polyester called cutin. Even plants that live under water in the oceans, such as Zoestra marina, are covered with cutin. This lipid-derived polyester covering is unique to plants, as animals use carbohydrate or protein polymers as their outer covering. Cutin, the insoluble cuticular polymer of plants, is composed of inter-esterified hydroxy and hydroxy epoxy fatty acids derived from the common cellular fatty acids and is attached to the outer epidermal layer of cells by a pectinaceous layer (Fig. 1). The insoluble polymer is embedded in a complex mixture of soluble lipids collectively called waxes [1], Electron microscopic examination of the cuticle usually shows an amorphous appearance but in some plants the cuticle has a lamellar appearance (Fig. 2). 

The improvement of its activity and stability has been approach by the use of GE tools (see Refs. [398] and [399], respectively). A process drawback is the fact that the oxidation of hydrophobic compounds in an organic solvent becomes limited by substrate partition between the active site of the enzyme and the bulk solvent [398], To provide the biocatalyst soluble with a hydrophobic active site access, keeping its solubility in organic solvents, a double chemical modification on horse heart cytochrome c has been performed [400,401], First, to increase the active-site hydrophobicity, a methyl esterification on the heme propionates was performed. Then, polyethylene glycol (PEG) was used for a surface modification of the protein, yielding a protein-polymer conjugates that are soluble in organic solvents. 

Gill, I. and Ballesteros A. (2000) Bioencapsulation within synthetic polymers (Part 2) non sol-gel protein-polymer biocomposites. Trends in Biotechnology, 18, 469-479. 

Trubetskoy, V.S., Narula, J., Khaw, B.A., and Torchilin, V.P. (1993) Chemically optimized antimyosin Fab conjugates with chelating polymers Importance of the nature of the protein-polymer single site covalent bond for biodistribution and infarction localization. Bioconjugate Chem. 4, 251-255. 

Attempts were also made to design non-protein polymers able to collapse to a globular conformation with properties complying (at least in part) with the given requirements e.g., having an active center [87]. The review of the research performed in this direction can be found in [88-92]. 

First plant-derived protein polymer - artificial elastin in tobacco 7... 

Enzyme catalysis. Enzymes are proteins, polymers of amino acids, which catalyze reactions in living organisms-biochemical and biological reactions. The systems involved may be colloidal-that is, between homogeneous and heterogeneous. Some enzymes are very specific in catalyzing a particular reaction (e.g., the enzyme sucrase catalyzes the inversion of sucrose). Enzyme catalysis is usually molecular catalysis. Since enzyme catalysis is involved in many biochemical reactions, we treat it separately in Chapter 10. 

Anderson, J. P., Cappello.J., and Martin, D. C. (1994). Morphology and primary crystal-structure of a silk-like protein polymer synthesized by genetically-engineered Escherichia-coli bacteria. Biopolymers 34, 1049-1058. 

Buchacher et al. [43] discussed the continuous separation of protein polymers from monomers by continuous annular size exclusion chromatography. The P-CAC used for the experiments was a laboratory P-CAC type 3 as described in Table 1. The results were compared to conventional batch column chromatography in regard to resolution, recovery, fouling, and productivity. The protein used in the studies was an IgG preparation rich in aggregates. Under the conditions used, the polymers could be separated from the monomers, although no baseline separation could be achieved in either the continuous or the batch mode. The... 

Proteins Polymers of amino acids linked by peptide bonds. The specific sequence of amino... 

We have prepared a synthetic protein polymer based on repeat sequence Lys-25 to investigate the effect of uniformity of crosslink placement on the physical properties of a polymer hydrogel (Figure 1). The design of Lys-25 reflects two essential structural requirements for formation of polymer hydrogels (1) a flexible, hydrated (polyamide) backbone and... 

Elastin-mimetic protein polymers have been fabricated into elastic networks primarily via y-radiation-induced, radical crosslinking of the material in the coacervate state [10]. Although effective, this method cannot produce polymers gels of defined molecular architecture, i.e., specific crosslink position and density, due to the lack of chemoselectivity in radical reactions. In addition, the ionizing radiation employed in this technique can cause material damage, and the reproducibility of specimen preparations may vary between different batches of material. In contrast, the e-amino groups of the lysine residues in polymers based on Lys-25 can be chemically crosslinked under controllable conditions into synthetic protein networks (vide infra). Elastic networks based on Lys-25 should contain crosslinks at well-defined position and density, determined by the sequence of the repeat, in the limit of complete substitution of the amino groups. 

Protein polymers based on Lys-25 were prepared by recombinant DNA (rDNA) technology and bacterial protein expression. The main advantage of this approach is the ability to directly produce high molecular weight polypeptides of exact amino acid sequence with high fidelity as required for this investigation. In contrast to conventional polymer synthesis, protein biosynthesis proceeds with near-absolute control of macromolecular architecture, i.e., size, composition, sequence, topology, and stereochemistry. Biosynthetic polyfa-amino acids) can be considered as model uniform polymers and may possess unique structures and, hence, materials properties, as a consequence of their sequence specificity [11]. Protein biosynthesis affords an opportunity to completely specify the primary structure of the polypeptide repeat and analyze the effect of sequence and structural uniformity on the properties of the protein network. 

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