Amino acid linkage influence

Influence of the Amino Acid Linkages on Intramolecular Electron-Transfer Rates. There is a significant drop in the 2... 

The amino acids in the cytoplasm will not form polypeptides unless activated by ester formation with appropriate tRNA molecules. The ester linkages are through the 3 -OH of the terminal adenosine nucleotide (Equation 25-9) and are formed only under the influence of a synthetase enzyme that is specific for the particular amino acid. The energy for ester formation comes from ATP hydrolysis (Sections 15-5F and 20-10). The product is called an amino-acyl-tRNA. 

In addition to the covalent peptide bonds formed between adjacent amino acids within a polypeptide chain, covalent disulfide bonds can be formed within the same polypeptide chain or between different polypeptide chains (fig. 3.11). Such disulfide linkages have an important stabilizing influence on the structures formed by many proteins (see chapter 4). 

The surprising feature of the absorption spectrum of phenylalanine is that it is sensitive to acid and alkali. This indicates that an appreciable change in the vibrational levels of the benzyl chromophor occurs, due to inductive effects brought about by ionization of the carboxyl or amino group. As will be shown later, such an influence on the vibrational levels can be shown to occur when an aromatic amino acid is combined in peptide linkage (Section VI, 2). The absorption curves of phenylalanine in acid and alkali are shown in Fig. 3. 

Hofmeister, Franz (1850-1922), physiological chemist and pioneer of protein structure. He succeeded Hoppe-Seyler at Strasbourg, where he led a productive research school. Franz Hofineister and EmU Fischer exerted both, each in his own way, a significant influence on the development of the biochemical sciences. Already in 1902, at a historical meeting at Karlsbad, Franz Hofineister first formulated scientifically the assumption of an amide-like linkage of the individual amino acids in proteins, four years before Fischer coined the term peptide [F. Hofmeister, Naturw. Rdsch. 1902, 17, 529]. 

Anticorrosion activity could be much more effectively influenced by the acyl moiety than by the amino acid, although amino dicarboxylic acids (aspartic acid, glutamic acid) provide an additional ionized group, which may strengthen the linkage between the inhibitor molecule and the metal surface covered by oxide/hydroxide, oxy-hydroxide, and salts. 

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