Alanine chemical structure

Keywords Quantum chemical calculations, L-Alanine, D-Alanine, Electronic structure, Net atomic charges, Bond length, Dipole moment. Fig. land Fig. 2 are the optimized structure of L-Alanine and D-Alanine with HF/6-31G... 

The many (possibly more than 30) types of collagens found in human connective tissues have substantially the same chemical structure consisting mainly of glycine with smaller amounts of proline and some lysine and alanine. In addition, there are two unusual amino acids, hydroxyproline and hydroxylysine, neither of which has a corresponding base-triplet or codon within the genetic code. There is therefore, extensive post-translational modification of the protein by hydroxylation and also by glycosylation reactions. 

The chemical structures of the amino acids found in soil-solids are shown in Fig. 6 [25] while the quantities of amino acids found in HS extracted from various solid phases are represented in Fig. 7 (data were collected from Ghosh and Schnitzer [37] and Schnitzer et al. [38]). High levels of amino acid nitrogen were found in HA, FA, and humin fractions, indicating incorporation of common acidic and some neutral amino acids, particularly glycine, alanine, and valine. 

The first consideration when investigating HPLC method development protocols is the chemical structure of the analyte, in particular, the presence of functional groups capable of interacting with the stationary phase and containing or in the vicinity of the stereogenic elements [79]. Since the natural target of macrocyclic antibiotics is the A-acyl-D-alanyl-D-alanine terminus (see Section 2.1), the early choice of suitable substrates for this kind of CSPs was that of amino acids [45]. However, it turned out that the macrocyclic CSPs were very successful not only in amino acids enantioresolution, but also in the separation of a wide variety of different structures. 

Twenty amino acids are commonly found in proteins, (a) Draw the chemical structures of alanine, glycine, phenylalanine, and cysteine (see Table 19.4). 

Figure 8.3 Chemical structure of alanine. Implicit hydrogens are omitted.

The analytical utility of near-infrared spectroscopy can be demonstrated by an analysis of mixtures composed of glucose, lactate, urea, alanine, ascorbate, and triacetin in a pH 6.8 aqueous phosphate buffer.6 The chemical structures of these test compounds are presented in Figure 13.2. These components were selected to represent different classes of molecules expected in typical biological matrices. Glucose represents carbohydrates lactate represents small organic acids urea is a... 

Figure 13.2 Chemical structures of alanine, ascorbate, glucose, lactate, triacetin, and urea.

Ionic Forms of Alanine Alanine is a diprotic acid that can undergo two dissociation reactions (see Table 3-1 for pAa values). (a) Given the structure of the partially protonated form (or zwitterion see Fig. 3-9) below, draw the chemical structures of the other two forms of alanine that predominate in aqueous solution the fully protonated form and the fully deprotonated form. 

III this case the two steps, 3-eliminati6n and hydrolysis of the resulting dehydro enzyme were done simultaneously. This procedure may facilitate the task of establishing the chemical structure of the active site of esterases and peptidases (cf. Cohen et al., 1959 cf. TomaSek et al., 1960 Sanger and Shaw 1960). Complications may arise here through base-catalyzed dis-mutations of pyruvoyl peptides, which are observed in the conversion of pyruvoylglycine into alanine by the action of base (Fu et al., 1952 cf. Wieland et al., 1958). 

BCAA catabolism, 209 chemical structure, 18 plasma concentrahon, 465 waste nitrogen and, 209-210 Alanine aminotransferase, 426 Alanine cycle, amino transferases and, 427-428... 

Residue The portion of a chemical structure (hat cun be idcnii-tled us coming from a porticuiar building block,. such as the alanine residue in a polypeptide. In u generic structure, (he residues arc (he. substituents that correspond to the R-gniup.s in the structure. 

Scheme 4 Chemical structures of poly(y-benzyl-L-glutamate)-b-poly(ethylene glycol)-b-poly(y-benzyl-L-glutamate) (PBLG-PEG-PBLG), poly(y-benzyl-L-asparate)-b-poly(ethylene glycol)-b-poly(y-benzyl-L-asparate) (PBLA-PEG-PBLA), poly(ethylene glycol)-b-poly(L-alanine) (PEG-PLA) and poly(ethylene glycol)-b-poly(DL-valine-co-DL-leucine) (PEG-poly( valine-co-leucine))...

The incorporation experiments by Birch and co-workers (33,34), using [2- C]mevalonic acid, L-[l- 4C]alanine, and L-tryptophan, provided valuable information for the structural elucidation. Echinulin possesses two asymmetric centers, l-Alanine is obtained by acid hydrolysis, but another chiral center on the tryptophan moiety is easily racemized. Later, it was determined as the l form by microbioassay of the aspartic acid obtained by ozonolysis (35). Finally, the chemical structure 12 was confirmed by the stereoselective total synthesis of optically active echinulin by Kishi and co-workers (36) (Scheme 5). 

Peptide hormones are produced by the endocrine glands (pituitary, thyroid, pineal, adrenal, and pancreas) or by various organs such as the kidney, stomach, intestine, placenta, or liver (Table 3.4). Peptide hormones can have complex, convoluted structures with hundreds of amino acids. Figure 3.2 illustrates the chemical structure of human insulin and its three-dimensional shape. Insulin is made of two amino acid sequences. The A-Chain has 21-amino acids, and the B-Chain has 30-amino acids. The chains are linked together through the sulfur atoms of cysteine (Cys). Peptide hormones are generally different for every species, but they may have similarities [11]. Human insulin is identical to pig insulin, except that the last amino acid of the B-Chain for the pig is alanine (Ala) instead of threonine (Thr) (lUPAC and lUBMB) [9] and [11]. 

The folding of a protein explained in the Introduction to this chapter creates an intertwined chemical structure. Ponnuswamy et al. (2012) fabricated knotted molecules, similar to protein structure, which took advantage of hydrophobic interactions. The molecular structure was comprised of three hydrophobic naphthalene diimides held together with alanine linkers and anchored at both ends with cysteine amino acid. 

Properties of some derivatized (5)-alanine compounds, ma represents molar absorptivity (k(v)) (mol cm ), X represents the wavelength of fluorescenee detection (nm). The sensitivity depended upon the chromatographic conditions. Chemical structures were from refs. 27 and 28. 

Chemical structure (Figure 11). Pantothenic acid is composed of ) -alanine and 2,4-dihydroxy-3,3-dime-thylbutyric acid (pantoic acid), linked acid-amidelike. 

Figure 7 Peptide sequences and chemical structures of amino acids and fluorophores. Shown are the sequences for peptides TBQ, TH2, TFl, and TF2 and structures of y3-alanine (single amino acid code B), the fluorescence donor NBD, and acceptor TAMRA. Leucine residues replaced by hexafluoroleucine in the peptide sequences are indicated in green.

FIGURE 25.1 Similarity in chemical structures between L-lactic acid and L-alanine. 

Fig. 2 Chemical structure of SMANCS, Two chains of SMA [copoly(styrene-maleyl-butylate-half-n-ester)] are attached to the N-terminal amino group of alanine 1 and the e-amino group of lysine 20 of NCS...

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

Figure 22 Chemical structures of (a) poly(hexylisocyanate) (d) poly(N,N -di- -hexylcarbodiimide) and (e) poly[(R/ S)-N-(l-phenylethyl)-N -methylcarbodiimide)]. (b) and (c) show the synthetic scheme of the removal of the ester functions of poly(isocyano-L-alanine-L-alanine) and poly(isocyano-L-alanine-L-histidine), respectively.

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