Polypeptide and Protein Synthesis

The most successful method of fragment condensation for the synthesis of polypeptides and proteins in solution phase is NCL, reported by Dawson for the first time in 1994 [7]. This was a significant contribution because NCL overcomes one of the main limitations of solid phase peptide synthesis (SPPS), namely the production of long peptide sequences (>50 amino acid residues) [1, 3, 29]. NCL may be used in both solution and solid phases solution phase NCL has been used for the synthesis of small peptides and cyclic peptides [30-32] whereas SPPS is more widely applied in polypeptide and protein synthesis. 

Acid-Base Properties of Amino Acids Poiypeptides and Proteins Primary Structure of Polypeptides and Proteins Synthesis of Polypeptides 27.6 Three-Dimensional Shapes of Polypeptides and Proteins... 

Prize in 1963 for inventing a new general method to synthesize important polymers, a method that uncovered much new basic science. A Nobel Prize in 1984 went to Robert Bruce Merrifield for his invention of a general approach to the synthesis of polypeptides and proteins, in a style directly reminiscent of the biological method used in such synthesis. 

Strategies for functionalization have been developed that exploit the naturally occurring amino acids as well as the non-natural ones. Post-synthetic modifications have been reported that are based on reactive sites that self catalyze the incorporation of the new functionality at the side chains of Lys residues [24,25] and on the chemoselective ligation reaction [26-29]. These developments in combination with new methodology for the synthesis of large proteins [30] provide access to a highly versatile pool of new polypeptides and proteins. 

Amino acids are monomeric units of polypeptides and proteins. They are widely used in the food and chemical industries as flavor enhancers, seasonings and sweeteners e.g. for the improvement of bread quality, also in the production of drugs, cosmetics, synthetic leather and surfactants, in medicine for infusions and as therapeutic agents. Amino acids are produced by chemical synthesis or extraction from protein hydrolyzate. They may be also produced by microbiological methods. 

Golub, E.S. and Green, D.R. (1991). Immunology A Synthesis (Sunderland, Massachusetts Sinauer Associates Inc.). Griffiths, E. (1991). Polypeptide production by recombinant DNA technology. In Polypeptide and Protein Drugs Production, Characterization and Formulation. R.C.Hider and D.Barlow, eds. (Chichester Ellis Horwood),... 

The preparation of polypeptides and proteins using automated peptide synthesis—the Merrifield method (Section 28,7) The structure of spider silk (Section 28.8B)... 

Development of the solid phase technique earned Merrifield the 1984 Nobel Prize in Chemistry and has made possible the synthesis of many polypeptides and proteins. 

The combination of sohd phase peptide synthesis with polymer chemistry has proven to be a versatile method for the preparation of polymer-peptide hybrids. Introduction of native ligation methods even allows the synthesis of polymer modified polypeptides and proteins via an entire organic chemistry approach. In the field of polymer chemistry—besides the advances in NCA polymerization, which will be discussed by others and is therefore not part of the scope of this review—controlled radical polymerization has been shown to be a robust technique, capable of creating well-defined biofunctional polymer architectures. Through protein engineering, methods have been estabhshed that enable the construction of tailor-made proteins, which can be functionalized with synthetic polymer chains in a highly defined manner. 

Da. The toxins are made up of two polypeptide chains (A and B) connected by a disulfide bond. The cytotoxicity of ricin is due to inhibition of protein synthesis, caused when the B chain binds to cell-surface receptors and the toxin-receptor complex is taken into the cell, and the A chain that has endonuclease activity and, at extremely low concentrations, will inhibit DNA replication and protein synthesis (USAMRICD, 2005). Ricin is stable under ambient conditions and can be detoxified by heat at 80°C for 10 min, or 50°C for an hour at a pH of 7.8. Chlorine inactivates over 99.4% by 100 mg/L FAC in 20 min. Low chlorine concentrations, such as 10 mg/L FAC, as well as iodine at up to 16 mg/L will have no effect on ricin (USAMRICD, 2005). 

Most polypeptides and proteins are water-soluble or water swellable. Enzymes are proteins that catalyze all chemical reactions of biological origin. Enzyme functions include oxygen transport, muscle movement, nerve response, nutrient digestion and storage, hormonal regulation gene expression, and protein synthesis. 

BSs protected cereal leaf cells from heat shock or saline stress. Leaf pre treatment with BSs decreased cell ultrastructure degradation from heat shock and high salt conditions. BSs increased HSG formation which is supposed to protect preformed mRNA in plant cells during heating. BSs enhanced heat shook resistance of the leaf protein-synthesizing system. The effect of BSs on RNA and protein synthesis was shown earlier (14). We observed protein synthesis activation in wheat leaves by BSs in normal and under stress conditions. Two-dimensional SDS-FAAGE of dS-methionine labeled proteins demonstrated BS-induced changes in the set of polypeptides synthesized in leaves and in the rate of their synthesis. 

It is known that protein synthesis is necessary for BR-induced effects in root tissue (25), and BR-treatment increases nucleic acid and protein synthesis in bean stem (26). In the pea stem segment, kinetic studies with selected protein and nucleic acid synthesis inhibitors showed no evidence for competitive inhibition in polypeptide chain elongation, post-transcriptional polyA addition to heterogeneous RNA, DNA-dependent RNA synthesis, or of the DNA-dependent RNA polymerase... 

Propachlor inhibits root and stem growth, cell division and protein synthesis, the last presumably by inhibiting the transfer of an enoacyl-jRNA into the polypeptide chain (Duke, 1968). Penner (1970) found inhibition of the phytase enzyme in squash treated with propachlor. 

While axonal transport and protein synthesis are essential for nerve regeneration (see review by Grafstein and Forman, 1980), the overall rate of fast transport is not affected by sciatic axotomy (Griffin et al., 1976 Bisby, 1978 Crescitelli et al., 1989). Despite this, there is an increase in the amount of small proteins and polypeptides, known as growth-associated-peptides (GAPs), destined to be incorporated in the regrowing plasma membrane and cy-toskeleton (Skene and Willard, 1981 Bisby, 1988). One of these GAPs is B-50, also known as GAP-43, which is discussed in Section 2.4. 

C-terminal peptide a-thioester, mUdly activated peptide ester acting as a valuable key intermediate for the synthesis/semi-synthesis of polypeptides and proteins by both chemical ligation and the Aimoto thioester approach. The synthesis of the peptide a-thioester (—r thioester) can be performed by standard SPPS using Boc- or Fmoc-based chemistry or, for larger target polypeptides, by application of intein-based bacterial expression systems. Peptide a-thioester synthesis can also be carried out based on an N-S acyl shift reaction mediated by a thiol ligation auxiliary [F. B. Perler, E. Adams, Curr. Opin. Biotechnol. 2000, 377 D. Swinnen, D. Hilvert, Org. Lett. 2000, 2, 2439 R. Quaderer, D. Hilvert, Org. Lett. 2001, 3, 3181 T. W. Muir, Annu. Rev. Biochem. 2003, 72, 249 T. Kawakami et al.. Tetrahedron Lett. 2005, 46, 8805 J. A. Camarero, A. R. Mitchell, Prot. Pept. Lett. 2005, 12, 723]. 

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