A-Amino adipic acid

Bailey AJ, Ranta MH, Nicholls AC, Partridge SM and Elsden DP (1977) Isolation of a -amino adipic acid from mature dermal collagen and elastin. Evidence for an oxidative pathway in the maturation of collagen and elastin. Biochem Biophys Res Comm 78, 1403-1410. 

The next member of this homologous series, a-amino-adipic acid, has been prepared by Sorensen from phthalimidosodium malonic ester and chlorobutyronitrile in the following way —... 

Table 2.1.8 The primary defects of amino acid metabolism and the corresponding changes of plasma or urine amino acid levels. AA amino acid, AAA a-amino-adipic acid,...

P-Lactam Antibiotics.—The tripeptide [as (159)] isolated from Penicillium chry-sogenum151 has been accepted as a likely key intermediate in the biosynthesis of penicillins with penicillin N (158), the first of the fi -lactams to be formed.152 It has been shown recently that this tripeptide is formed from radio-active L-a-amino-adipic acid, L-valine, and L-cysteine in P. chrysogenum and has the absolute configuration (159).153 Moreover, it has been shown to be a precursor for penicillin... 

The penicillins, from the fungus Penicillium chryso-genum, are the oldest and most widely used antibiotics. They are formed through stepwise build-up from a tripeptide (ACV) derived from a-Amino adipic acid, cysteine, and valine. Successive oxidation steps form the p-lactam and close the thiazolidine ring to form isopenicillin N. Action of an acyltransferase then yields penicillin G (Fig. 47). Alternatively, hydrolysis of isopenicillin N (or penicillin G) yields 6-aminopenicillanic acid, a key precursor for the wide range of semisynthetic pencillins used therapeutically. 

Substances related to MSG and purine 5 -ribonucleotides include peptides, amino acids (e.g. cysteine, homocysteine, cysteine S-sulfonic acid, aspartic acid, a-amino adipic acid, a-methyl glutamic acid, tricholomic acid, ibotenic acid), pyrrolidone carboxylic acid, 3-methyl thiopropyl amine, and others [2, 10], They are of less commercial interest than MSG, IMP, and GMP. Chemical structures of some of these substances are depicted in Fig. 3.53. Relative umami effects of some are shown in Tab. 3.49. Tricholomic acid and ibotenic acid have been found in the mushrooms Tricholoma muscarium and Amanita stroboliformis, respectively. 

Possibly formed by reaction of lysine and a-amino adipic acid 8-semi aldehyde... 

Formed from condensation of two a-amino adipic acid 8-semialdehyde residues... 

The numerous cross-linkages found in collagen are the result of the oxidation of lysine and hydroxylysine to a-amino adipic acid 8-semialde-hyde (allysine) and 8-hydroxy a-amino adipic acid 8-semialdehyde (hy-droxyallysine), respectively, following the assemblage of the collagen chains into the macromolecular structure (Equations 4 and 5) ... 

The cross-linkages found in collagen and elastin arise from the non-enzymatic interaction of a-amino adipic acid 8-semialdehyde (AL) and 8-hydroxy a-amino adipic acid 8-semialdehyde (HAL) with another residue of the aldehyde or with lysine, hydroxylysine, or histidine residues located at specific positions in the collagen polypeptide chains. Possible relationships among the different compounds in Table II are shown in Figures 4 and 5 for collagen and elastin. 

Homoserine also has been detected in filtrates of liver preparations incubated with methionine. Cantoni provisionally identified homoserine as a product of the acid hydrolysis of active methionine (S-adeno-sylmethionine). Beyond homoserine, the postulated reactions 2 and 3 are still more speculative. It might be presumed that homoserine is oxidized to aspartic acid, in analogy to the observations on the catabolism of lysine, in which the analogous a-amino adipic acid is an intermediate. If aspartic acid is formed, the subsequent reaction sequence is readily apparent. Evidence favorable to the proposed reaction pathway is the finding of Marshall and Friedberg, of the occurrence of a small amount of fumaric acid, labeled in the methine carbons, from the livers of mice injected with DL-methionine-2-C. ... 

Side-chain precursors. The incorporation of isotope from deuterophenylacetyl-valine and from phenylacetic acid-1into benzylpenicilUn by P. chrysogenum showed that added phenylacetic acid and some of its derivatives were direct precursors of the penicillin side-chain (Behrens, 1949 Sebek, 1953 Halliday and Arnstein, 1956). The use of DL-a-amino-adipic acid-2- C and 6- C has indicated that free exogenous a-aminoadipic acid can be incorporated into the side-chain of penicillin N by the Cephalosporium sp. (Abraham et al., 1964). However, the isotope from added L-a-aminoadipic acid-6- C was incorporated into the antibiotic much more efficiently than that from the corresponding D-isomer. 

L-a-Aminoadipic acid is presumably the precursor of the 3-(L-a-aminoadipoyl)-side-chain of isopenicillin N formed by P. chrysogenum. Free a-aminoadipic acid isolated from the mycelium of this organism was found to be predominantly the L-isomer (Arnstein and Morris, 1960c). But L-a-aminoadipic acid- C added to the extracellular fluid of the Cephalosporium sp. is also a better precursor than the D-isomer of the 3-(D-a-aminoadipoyl) side-chain of penicillin N and cephalosporin C (Abraham et al., 1964). The does not appear to be due merely to the fact that L-a-aminoadipic acid enters the mycelium much more rapidly than D-a-amino-adipic acid. Added L-a-aminoadipic acid may be diluted in the amino acid pool of the mycelium by endogenous L-a-aminoadipic. The latter is synthesized by the Cephalosporium sp. from acetyl coenzyme A and a-oxoglutarate by the following route through homoisocitric acid (Trown et al., 1962 Trown et al., 1963), which is that by which it is also synthesized in yeast (Strassman and Ceci, 1964 Strassman, Ceci and Silverman, 1964) ... 

Arnstein, H. R. V., and D. Morris The structure of a peptide, containing a-amino-adipic acid, cystine and valine, present in the mycelium of Penicillium chrysogenum. Biochem. J. 76, 357 (1960c). 

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