Biologically active proteins

The information which specifies the amino-acid sequence of a protein is stored in the nucleotide sequence of the double helix of deoxyribonucleic acid (DNA). The transcription of sections of this information into ribonucleic acid (RNA) is catalysed by RNA polymerases. These enzymes not only control the synthesis of RNA but also recognize stop and start signals on the DNA. The start signals are complex and may be blocked by repressor molecules which inhibit the transcription process. Once synthesized, the (messenger) RNA is processed and exported to ribosomes where its nucleotide sequence is translated into protein. Triplets of three nucleotides (codons) in the messenger RNA each specify (encode) one amino acid. The linear sequence of nucleotides in the messenger RNA thus specifies the sequence of amino acids in the protein whose primary structure will therefore correspond directly to the sequence of nucleotides in the DNA. 

The micro-organisms can synthesize only the proteins already encoded in 

The commercial production of proteins from micro-organisms began in the United States around 1890 when Takamine introduced a traditional Japanese fermentation process for takadiastase. This product, which was derived from Aspergillus niger (cf. section 6.2.2.2) was a mixture of enzymes which catalysed the hydrolysis of starches and proteins. Some years later, in 1913, Boidin and Effront discovered that Bacillus subtilis produces a heat-stable a-amylase. This enzyme also catalyses the hydrolysis of starches, and was used in the textile industry for desizing cloth. 

The enzymes which catalyse the hydrolysis of proteins and starch remain the major bulk proteins with biological activity which are derived from microorganisms (Table 6.13). The proteases have many uses (Table 6.14), but the list is little different to that which Webb recorded in his review of biochemical engineering in 1964. The enzymes, such as a-amylase and amyloglucosidase, which catalyse the hydrolysis of starch, are important for the manufacture of sugar (section 6.6.1). Since this is one stage in the synthesis of ethanol from starch (section 6.2.1.1) their current production is likely to be much greater than it was in 1979. 

At the other end of the scale of production are the pharmacologically active proteins. In 1982 the United States Office of Technology Assessment 

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The protein folding problem is the task of understanding and predicting how the information coded in the amino acid sequence of proteins at the time of their formation translates into the 3-dimensional structure of the biologically active protein. A thorough recent survey of the problems involved from a mathematical point of view is given by Neumaier [22]. 

Proteins and Meals. Nutritional properties of the oilseed protein meals and their derived products are deterrnined by the amino acid compositions, content of biologically active proteins, and various nonprotein constituents found in the defatted meals. Phytic acid (3), present as salts in all four meals, is beheved to interfere with dietary absorption of minerals such as 2inc, calcium, and iron (67) (see Food toxicants, naturally occurring Mineral nutrients). ... 

Crameri, R., and Suter, M. (1993). Display of biologically active proteins on the surface of filamentous phages a cDNA cloning system for selection of functional gene products linked to the genetic information responsible for their production. Gene 137, 69-75. 

The term polyproteins is used for two different types of entity. The first refers to precursor polypeptides which are cleaved post-translationally into biologically active proteins or peptides of quite different functions. Examples of these include polyproteins of viruses and some prohormones of vertebrates (reviewed in Kennedy, 2000b). The other type is large proproteins which comprise tandem repetitions of identical or similar polypeptides that are post-translationally cleaved into multiple copies of biochemically similar functional entities. The nematode polyprotein allergens/antigens (NPAs) fall into this class (Fig. 16.1). 

Fischer, brilliant results were achieved, and in succession the a-amylases of pig pancreas, of Bacillus subtilis, of human saliva, of human pancreas, and of Aspergillus oryzae, and the /3-amylase of malt, were successfully crystallized. Important biological deductions were gained from this study whereas the amylases of human pancreas and saliva cannot be distinguished from one another, amylases from pig pancreas and from human pancreas are different. These differences are manifested in molecular weight, crystalline forms, electrophoretic mobility, and influence of the pH on the activity however, all the amylases have the same specific biochemical action. The identity of the enzymes seems to be dependent on the species and not on the organ. Interest in biologically active proteins led Meyer to a study of the protein hormones, a field in which he was very active at the time of his death. 

The Ras proteins are synthesized as biologically inactive, cytosolic precursor proteins. They are then modified by several post-translational processing steps at the carboxyl terminal end and thereby converted into biologically active proteins localized at the plasma membrane. The cysteine of the C-terminal CAAX sequence (C is cysteine, A is generally an aliphatic amino acid, and X is methionine, serine, alanine, or glutamine) is first enzymatically S-farnesylated the AAX part is then cleaved off by a specific protease, and the free C-terminal cysteine is finally converted into a methyl ester (Scheme 1). 

Schwarze SR, Ho A, Vocero-Akbani A, Dowdy SE. In vivo protein transduction delivery of a biologically active protein into the mouse. Science 1999 285(5433) 1569-1572. 

Schwarze SR, Dowdy SF. In vivo protein transduction intracellular delivery of biologically active proteins, compounds and DNA. Trends Pharmacol Sci 2000 21(2) 45-48. 

Bioteehnology produets differ in their method of preparation and potential problems they present in their formulation. Pharmacists involved in compounding with biologically active proteins are interested in their stabilization, formulation, and delivery. Most of the current biotechnology products are proteins, but soon some may be smaller peptide-like molecules. 

Abstract. The hybrid cell lines, which we have obtained, can be widely used in veterinary virology and biotechnology for preparing vaccines, test-systems for viruses. Any strains of hybrid cells are producing the biological active proteins (enzymes and others). We have obtained hybrid cell lines (PO-TKxCO, PO-TKxHO), which are sensitive to prion protein, and also hybrid culture with P-cells of the pancreas of rabbit. 

Mine Y, Kovacs-Nolan J. (2006) New insights in biologically active proteins and peptides derived from hen egg. World s Poultry SciJ 62 87-96. 

Controlled expression of genes coding for biologically active proteins in prokaryotes and eukaryotes, including transformed mammahan cells... 

The first step in the process was to covalently incorporate biologically active protein molecules into this polymer. Methods analogous to previous reports (4-6) involved first adding a functional group to the protein that would provide it with the ability to polymerize, such as a vinyl or substituted vinyl group, followed by copolymerization with the N-isopropylacrylamide monomer in aqueous solution using N,N,N, N -tetramethylethylenediamine and... 

Shami, E.Y., Rothstein, A. and Ramjeesingh, M. (1989) Stabilization of biologically active proteins. Trends in Biotechnology, 7, 186-190. 

Bnrton, M., H. Nakai, P. Colosi, I Cnnnmgham, R. Mitchell, and L. Conto, Coexpression of factor VIII heavy and light chain adeno-associated viral vectors produces biologically active protein. Proc Natl Acad Sci USA, 1999. 96(22) 12725-30. 

Teng, C.D., Zarrintan, M.H., and Groves, M.J. (1991). Water vapor adsorption and desorption isotherms of biologically active proteins. Pharm. Res., 8(2), 191-195. 

Bucher DJ, Palase P. The biologically active proteins of influenza virus neuraminidase. In ... 

In living cells, proteins are assembled from amino acids at a very high rate. For example, E. coli cells can make a complete, biologically active protein molecule containing 100 amino acid residues in about 5 seconds at 37 °C. How does such a polypeptide chain arrive at its native conformation Let s assume conservatively that each of the amino acid residues could take up 10 dif-... 

The amino acid units that make up a protein molecule are joined together in a precise sequence when the protein is made on a ribosome. The chain is then folded, often into a very compact form. Sometimes the chain is then cut in specific places. Pieces may be discarded and parts may be added. A metal ion, a coenzyme derived from a vitamin, or even a single methyl group may be attached to form the biologically active protein. The final product is a complex and sophisticated machine, often with moving parts, that is exquisitely designed for its particular role. 

Besides peptides, marine organisms have been reported to produce biologically active proteins, which are probably involved in the protection of organisms against physiological and stress conditions. Recently, these molecules have been cloned from sponges [324] and marine microorganisms [325],... 

Phase transition in gels in response to biochemical reactions [27,28]. Polymer gels were synthesized in which an enzyme (urease) or a biologically active protein (lectin) was immobilized. The volume phase transitions were observed in such gels when biochemical reactions took place. Such mechano-biochemical gels will be used in devices such as, sensors, selective absorbers, and biochemically controlled drug release. 

Production of human and animal health-care products, food products, biologically active proteins, and chemicals. 

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