Biological expression product

In this review, we focus on the use of plant tissue culture to produce foreign proteins that have direct commercial or medical applications. The development of large-scale plant tissue culture systems for the production of biopharmaceutical proteins requires efficient, high-level expression of stable, biologically active products. To minimize the cost of protein recovery and purification, it is preferable that the expression system releases the product in a form that can be harvested from the culture medium. In addition, the relevant bioprocessing issues associated with bioreactor culture of plant cells and tissues must be addressed. 

Expression product—a product encoded by a specific RNA molecule. An RNA fragment may encode a protein, its sequence, and may have a regulatory or biological function. 

The crucial decision in the choice of an expression host is its adequateness to produce a biologically active product. Activity includes not only the biological efficacy in vitro, but also the pharmacokinetic and immunological properties which influence the dose and side-reactions in animals and man. While some of these properties are not predictable a priori, accrued experience and the extent of knowledge regarding the... 

Catabolism of vitamin D is initiated by the enzyme vitamin D 24-hydroxyla.se. whose expression is stimulated by I o. 25-OHD3 itself. 24-Hydroxylation is followed by oxidation to the ketone. Subsequent hydroxylation at C-23 leads to cleavage of the side chain, resulting in the biologically inactive product calcitronic acid. ... 

The biologically important product of the reaction, however, is light. Chromophoric accessory proteins that are expressed with luciferase modulate the color of emitted light. Other proteins including flavin reductases and enzymes that recycle the fatty acid back to the aldehyde are also expressed." " ... 

All strategies for the production of genetically engineered polymers rely on the basic principle of self-figation (concata-merization) of DNA monomers to form concatameric DNA sequences (3,4). These concatamers are then cloned into the appropriate plasmid and introduced into a biological expression system, where they are transcribed and translated by the ceUrdar machinery to produce a protein-based pol3nner. 

Cells are often implanted or seeded into an artificial structure capable of supporting three-dimensional tissue formation. These structures, typically called scaffolds, are often critical, both ex vivo as well as in vivo, to recapitulating the in vivo milieu and allowing cells to influence their own microenvironments. Scaffolds usually serve at least one of the following purposes (i) allow cell attachment and migration, (ii) deliver and retain cells and biochemical factors, (iii) enable diffusion of vital cell nutrients and expressed products, and (iv) exert certain mechanical and biological influences to modify the behavior of the cell phase. 

DNA sequence information is the starting poiat for other appHcations, including the expression of a gene product, the search for related sequences ia biological samples, in vitro mutageaesis of the sequeace, and stmcture—function studies of gene expression. 

Enzymes are excellent catalysts for two reasons great specificity and high turnover rates. With but few exceptions, all reac tions in biological systems are catalyzed by enzymes, and each enzyme usually catalyzes only one reaction. For most of the important enzymes and other proteins, the amino-acid sequences and three-dimensional structures have been determined. When the molecular struc ture of an enzyme is known, a precise molecular weight could be used to state concentration in molar units. However, the amount is usually expressed in terms of catalytic activity because some of the enzyme may be denatured or otherwise inactive. An international unit (lU) of an enzyme is defined as the amount capable of producing one micromole of its reaction product in one minute under its optimal (or some defined) reaction conditions. Specific activity, the activity per unit mass, is an index of enzyme purity. 

The determined macro- and microelement stmcture of mumio specifies onto the expediency of the application of this biologically active substance as a cosmetic raw material in the cosmetic compositions, which do not contain carbopol. The developed procedure for calcium and sodium ions determination in pectin-containing vegetative extracts is express and it is recommended for application at elaboration of cosmetic production compositions on the carbopol base. 

One of the most important tasks in Analytical chemistry is the effective and express microquantity determination of toxic metals and biologically active organic materials in different objects of environment, raw materials and products of food technology and biotechnology. 

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