Amino add table

Proteins, as we learned in Chapter 16, are polymers of amino acids (Figure 18-7). They serve a host of different functions in the body, many more than carbohydrates. Human proteins are composed of 20 different kinds of amino acids, about half of which can be synthesized by the body itself. The other half, called the essential amino adds (Table 18-1), must come from food. Foods that are high in proteins include meat, cheese, eggs, milk, grains, legumes, and nuts. 

The long, repetitive sequence of —N—CH-CO- atoms that make up a continuous chain is called the protein s backbone. By convention, peptides are written with the N-terminal amino acid (the one with the free -NH3 1 group) on the left and the C-terminal amino acid (the one with the free -C02 group) on the right. The name of the peptide is indicated by using the abbreviations listed in Table 26.1 for each amino add. Thus, alanylserine is abbreviated Ala-Ser or A-S, and serylalanine is abbreviated Ser-Ala or S-A. Needless to say, the one-letter abbreviations are more convenient than the older three-letter abbreviations. 

Of the 20 common amino adds, ten are essential in the sense that they are required by humans for protein construction and cannot be synthesized in the body. These are designated by an asterisk in Table 23.3. Clearly the proteins we eat should contain these essential amino adds. Beyond that, a high-quality protein contains the various amino adds in the... 

Table 5.1 Example of organic acids produced commercially by micro-organisms organic adds considered in this chapter are labelled with. A related add, a-oxoglutaric acid, is easy to produce microbiologically but has no current end use succinic acid is produced chemically. Amino adds are beyond the scope of this chapter.

Amino adds are, therefore, important as nutrients (food and feed), as seasoning, flavourings and starting material for pharmaceuticals, cosmetics and other chemicals. They can be produced in a variety of ways (see Table 8.1) ... 

Of the amino adds isolated from living material, only about 20 are naturally occurring components of proteins. Some of these are shown in Table 8.2. The remainder, non-proteinogenic amino acids, are found as intermediates or end products of metabolism. 

Amino adds produced by fermentation on an industrial scale are listed in Table 8.3. 

Table 8.3 Amino adds industrially produced by fermentation.

The eight essential amino adds are listed immediately after Table 8.2. 

Table 9.3. Selected amino add profiles (concentrations in nmol %).

Amino adds find apphcations as ingredients of infiision solutions for parenteral nutrition and individnally for treatment of specific conditions. They are obtained either by fermentation processes similar to those used for antibiotics or in cell-fiee extracts employing enzymes isolated fiom bacteria (Table 25.1). Details of the mar and varied... 

X=Br) can be efficiently recovered from aqueous solution of the work-up for reuse.1241 Utilizing this N-anthracenylmethyl technology, various amino add derivatives have been synthesized by Lygo and coworkers in 40-86 % yields with 67-94 % ee as the N-free tert-butyl esters 25 and by Corey and coworkers in 67-91% yields with 92-99.5% ee as the imines 24, respectively. Some representative results are shown in Table 2... 

Gene expression and DNA replication are compared in Table I-l-l. Transcription, the first stage in gene expression, involves transfer of information found in a double-stranded DNA molecule to the base sequence of a single-stranded RNA molecule. If the RNA molecule is a messenger RNA, then the process known as translation converts the information in the RNA base sequence to the amino add sequence of a protein. 

Most genetic code tables designate the codons for amino adds as mRNA sequences (Figure 1-4-1). Important features of the genetic code include ... 

The 10 amino adds listed in Table 1-8-1 cannot be synthesized in humans and therefore must be provided from dietary sources. These are called the essential amino adds. Arginine is required only during periods of growth, or positive nitrogen balance. 

This enzyme is found in many tissues, where it catalyzes the reversible oxidative deamination of the amino acid glutamate. It produces the citric acid cycle intermediate a-ketoglutarate, which serves as an entry point to the cycle for a group of glucogenic amino adds. Its role in urea synthesis and nitrogen removal is stiU controversial, but has heen induded in Figure 1-17-1 and Table 1-17-1. 

Table 1-17-5 identifies some important products formed from amino acids. Table 1-17-5. Products of Amino Adds...

Table 8 1 The 21 amino adds present in mammalian proteins...

Figure 8.4 General summary of metabolism of amino adds. Amino adds in blood can be derived from the diet or hydrolysis of endogenous protein. The nitrogen in the amino acids can be used to synthesise other nitrogen-containing compounds (e.g. glutamine - see Table 8.4) or removed as urea (Chapter 10). The amino acids are also used to synthesise proteins or peptides. The carbon can be converted to CO2, glucose or triacylglycerol, but, in humans, very little is converted into fat, so triacylglycerol is omitted from the figure.

Figure 8.13 The central role of transdeamination in metabolism of amino adds and further metabolism of the oxoacids in the liver. The box contains the reactions for conversion of the amino acids to their respective oxoacids. Processes are as follows (1) digestion of protein in the intestine and absorption of resultant amino acids, (2) degradation of endogenous protein to amino acids (primarily but not exclusively muscle protein), (3) protein synthesis, (4) conversion of amino acid to other nitrogen-containing compounds (see Table 8.4), (5) oxidation to CO2, (6) conversion to glucose via gluconeogenesis, (7) conversion to fat.

For Trichoderma reesei the cellulases most thoroughly investigated with respect to their structural properties are CBH I and CBH II and to a lesser extent the two en-doglucanases (EG I and EG III) 11 (Table I). For most other cellulases structural characterizations are confined to the amino add sequence as deduced from the base sequence of the respective genes and to sequence related investigations such as hydro-phobic cluster analysis 10 or computer aided molecular modelling and homology... 

Table 13.2 pKs values for free and protein-bound amino adds... 

Table 1. Sequence comparisons of potential ATP binding sites in PKC isoenzymes and PGP (Amino adds occurring in both, PKC and PGP, in a similar position are printed in bold)...

Table 2 Add Hydrolysis of Peptides and Proteins Containing Unstable Amino Add Residues1131417-19 ...

Table 46 Actinide (IV) Compounds with Amino Adds...

Table 2 contains some examples of TTN oxidative coupling reactions. These examples show that the reaction can often tolerate unprotected amino add side chains, and that both 14- and 17-membered cycloisodityrosines can be obtained. In addition, the TTN oxidative coupling has been employed in the formation of 16-membered cyclic biaryl ethers of the type found in vancomycinJ20,21 The drawbacks of TTN oxidative coupling are the low yields, the formation of byproducts, and the need for additional transformations to arrive at the cycloisodityrosine target. 

Table 4 Ai-Z-iV-Methyl Amino Acids and /V-Methyl Amino Adds Prepared by the Oxazolidin-5-one Method 10310 107 ...

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