Serine chemical structure

An antipsychotic agent with a chemical structure somewhat similar to that of tioperidone (59) is ket an serin (68). The synthesis involves the straightforward thermal alkylation of... 

After the first successful attempts in 1928 to identify the active biochemicals found in antibacterial molds, followed the rediscovery of penicillin by Fleming, identification of its chemical structure by Hodgkin, and subsequent synthesis by Chain, Heatley, and Florey, which led to the commercial production of penicillin in the mid 1940s [1], Since then, other families of (3-lactam antibiotics have been developed [2, 3], and their massive use worldwide continues to be a forefront line of action against infectious pathogens [4-6]. In recent years, (3-lactams have found other biomedical applications, such as inhibitors of serine protease ([7, 8] for a review, see [9]) and inhibitors of acyl-CoA cholesterol acyltransferasa (ACAT) [10]. Encouraged by their bioactivity, the synthesis and chemistry of (3-lactam antibiotics have been the focus of active research, and chemical modification of some basic structures available from biosynthesis (semisynthetic approaches) as well as the discovery of fully chemical routes to de novo synthesis of (3-lactam... 

Hemendmince oj mechanisms past. Acetylcholinesterase converts acetylcholine into acetate and choline. Like serine proteases, acetylcholinesterase is Inhibited by DIPF. Propose a catalytic mechanism for acetylcholine digestion by acetylcholinesterase. Show the reaction as chemical structures. 

Fales and Pisano (1964) have discussed the gas chromatography of amines, alkaloids, and amino acids. Pollock and Kawauchi (1968) have resolved derivatives of serine, hydroxyproline, tyrosine, and cysteine, as well as racemic aspartic acid and tryptophan. VandenHeuvel and Horning (1964) have listed derivatives of steroids that can be separated. VandenHeuvel et al. (1960) first described the separation of bile acid methyl esters and Sjovall (1964) has extended the methods to bile acids. Gas liquid chromatography (GLC) is useful in the analysis of pesticides, herbicides, and pharmaceuticals (Burchfield and Storrs, 1962). Analysis of alkaloids, steroids, and mixtures of anesthetics and expired air are other examples of the application of this very useful technique. Beroza (1970) has discussed the use of gas chromatography for the determination of the chemical structure of organic compounds at the microgram level. 

Figure 4.2 Self-assembling peptide amphiphiles (PA) used for biomimetic mineralization of HA/PA nanocomposite, (a) Chemical structure of the PA, comprising 5 regions (1) a hydrophobic alkyl tail (2) four cysteine residues that can form disulfide bonds to polymerize the self-assembled structure (3) a flexible linker region of three glycine residues (4) a single phosphorylated serine residue that was able to interact strongly with calcium ions and help direct mineralization of HA (5) the cell adhesion ligand ROD. (b) Molecular model of one single PA molecule, (c) Schematic showing the self-assembly of PA molecules into a cylindrical micelle.

The chemical structure of phosphatidyl serine. J. biol. Chem. 174, 439 (1948). 

Figure 1.3 Repeating chemical structure of silk fibroin, composed of the amino acid sequence glycine-serine-glycine-alanine-glycine-alanine. ...

Figure 19.7 Chemical background, (a) Schematic chemical structure of native silaffin-IA (pH 5). (Adapted from Ref. [56].) (b) Silicatein topology and the key role of the hydroxy group of serine-26 and the imidazole side chain of histidine-165 in the proposed mechanism for silicatein-mediated catalysis. (Adapted from Ref. [1001.)...

In wool and silk fibers, intermolecular bonds are so extensive that the polymers cannot melt. When heated, the primary bonds on the main chains break before all intermolecular bonds can be damaged. As a result, both wool and silk behave like thermosetting polymers. However, the ability for wool and silk fibers to form intermolecular bonds is different. As shown in Table 4.4, the chemical stracture of silk is relatively simple and contains mainly residues of four types of amino acids glycine, alanine, serine, and tyrosine. Wool has a more complex chemical structure and consists of many different types of amino acid residues. As a result, more types of intermolecular bonds can be found in wool fibers. 

FIGURE 5.3 Chemical structures of 2-arylpropionic acids tested on silica gel G layers impregnated with L-serine. 

FIGURE 12.7 Chemical structures of Marfey s reagent and FDAA derivatives of serine. 

Absolute configurations of the amino acids are referenced to D- and L-glyceraldehyde on the basis of chemical transformations that can convert the molecule of interest to either of these reference isomeric structures. In such reactions, the stereochemical consequences for the asymmetric centers must be understood for each reaction step. Propose a sequence of reactions that would demonstrate that l( —)-serine is stereochemically related to l( —)-glyceraldehyde. 

Until recently, the catalytic role of Asp ° in trypsin and the other serine proteases had been surmised on the basis of its proximity to His in structures obtained from X-ray diffraction studies, but it had never been demonstrated with certainty in physical or chemical studies. As can be seen in Figure 16.17, Asp ° is buried at the active site and is normally inaccessible to chemical modifying reagents. In 1987, however, Charles Craik, William Rutter, and their colleagues used site-directed mutagenesis (see Chapter 13) to prepare a mutant trypsin with an asparagine in place of Asp °. This mutant trypsin possessed a hydrolytic activity with ester substrates only 1/10,000 that of native trypsin, demonstrating that Asp ° is indeed essential for catalysis and that its ability to immobilize and orient His is crucial to the function of the catalytic triad. 

The primary structure of a polypeptide is its sequence of amino acids. It is customary to write primary structures of polypeptides using the three-letter abbreviation for each amino acid. By convention, the structure is written so that the amino acid on the left bears the terminal amino group of the polypeptide and the amino acid on the right bears the terminal carboxyl group. Figure 13-35 shows the two dipeptides that can be made from glycine and serine. Although they contain the same amino acids, they are different molecules whose chemical and physical properties differ. Example shows how to draw the primary stmcture of a peptide. 

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