Medical applications amino acids

Chapter 9 shows the importance of PLC in the critical field of medical research, with representative examples of the applications to amino acids, carbohydrates, lipids, and pharmacokinetic studies. 

SA Adibi. In GL Blackburn, JP Grant, NR Young, J Wright, eds. Amino Acids Metabolism and Medical Applications, Boston PSG, 1983, pp 255-263. 

You probably studied acid-base chemistry as part of your undergraduate studies. However, acids and bases play such a key role in medicine and physiology that we believe the subject merits another look. The central theme in acid-base chemistry is relatively simple. Acids donate hydrogen ions to bases. The uses of this reaction are myriad in variation and in application. By controlling the acid-base conditions, you can ensure that a medication stays in solution. If the acid content of blood changes by a tiny amount, the patient dies. The acidic and/or basic properties of amino acids located in the active site of an enzyme catalyze a staggering number of chemical transformations which are essential for life. 

In summary we underline the fact that as far as urine analysis is concerned, and this is also true for blood, the most satisfactory results published so far are those obtained with Moore and Stein s 1954 procedure (see (b) Dowex 50-X4 columns) whereas the two latest improvements in technique open the way to much wider investigation in this field of biochemical and medical research. The technique is also applicable for the determination of a single amino acid, adequate shortcuts and simplifications in the procedure being introduced accordingly. As examples, we shall mention that appropriate rapid operations have been described for the separation on ion exchange columns and subsequent determination of (3-alanine (C20), (3-aminoisobutyric acid (E5) or y-aminobutyric acid (W1). Similar adjustments may also be made for other amino acids, such as the basic amino acids, for instance, with Moore and Stein s 1954 procedure (M15). 

IGF is a polypeptide of 70 amino acids, with three disulfide bonds and a molar mass of 7.6 kDa. Its therapeutic use is still under study and future medical applications for this protein are likely to be the treatment of dwarfism, diabetes type 2, and renal diseases, among others. 

Recognition of a specific amino acid sequence from a protein or a specific tag peptide sequence is expected to lead to variety of medical and materials applications. Whereas the recognition of a single amino acid residue by synthetic hosts has been reported previously, the artificial recognition of a sequence of two or more amino acid residues has been quite limited. There are only a few reports on the... 

L-Tryptophan (L-Trp) was produced, mainly by Japanese companies, on a scale of 500-6001 a-1 in 1997 [70]. It is an essential amino acid that is used as a food and feed additive and in medical applications. L-Trp is, at US 50 kg-1 (feed quality), the most expensive aromatic amino acid and it is thought that the market for L-Trp could expand drastically if the production costs could be brought down. There is no chemical process for L-TrP and enzymatic procedures starting from indole, which were very efficient, could not compete with fermentation [95]. L-Trp has been produced by precursor fermentation of anthranilic acid (ANT, see Fig. 8.16), but the serious effects of minor by-products caused the process to be closed down. Since the mid-1990s all L-Trp is produced by de novo fermentation. 

Nonstandard amino acids can be either incorporated globally at multiple sites within a protein or inserted at specific locations (1, 15). Global misincorporation of nonstandard amino acids can produce protein polymers with altered physical properties that confer, for example, varied tensile strengths and elasticities (16). These unique biomaterials can be used in many medical applications, such as altering properties associated with cell adhesion. In other applications, routine replacement of methionine by selenomethionine aids in X-ray crystal structure determination. 

HPLC life science applications focus on the separation, quantitation, and purification of biomolecules such as proteins, peptides, amino acids, nucleic acids, nucleotides, and polymerase chain reaction (PCR) amplification products.31 34 These are diversified and active research areas in medical research and drug discovery. 

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