Disease relevance of alanine

• Spherical E. coli due to elevated levels of D-alanine carboxypeptidase [1].
• METHODS: In HTC rat hepatoma cells, oxidative stress was produced by exposure to H(2)O(2) or D-alanine plus D-amino acid oxidase (40 U/mL) [2].
• Thus, D-alanine and D-serine are toxic to plants, but are metabolized by DAAO into nontoxic products, whereas D-isoleucine and D-valine have low toxicity, but are metabolized by DAAO into the toxic keto acids 3-methyl-2-oxopentanoate and 3-methyl-2-oxobutanoate, respectively [3].
• Isolation of the penicillin-binding peptide from D-alanine carboxypeptidase of Bacillus subtilis [4].
• No transpeptidase or D-alanine carboxypeptidase activity was detected in mixtures of high molecular weight penicillin-binding proteins from B. subtilis, B. stearothermophilus, or Staphylococcus aureus [5].

Psychiatry related information on alanine

• Bilateral injection of D-alanine, but not L-alanine, (10-100 micrograms per side for each amino acid) into the lateral ventricle reduced the increasing effect of phencyclidine (PCP, 10 mg/kg, given intraperitoneally) on locomotor activity in the rat in a dose dependent manner [6].

High impact information on alanine

• In these cloned cDNAs, the alanine codon GCG occurred at the position where D-alanine is present in the end product [7].
• The gene named ldcA encodes a cytoplasmic L, D-carboxypeptidase, which releases the terminal D-alanine from L-alanyl-D-glutamyl-meso-diaminopimelyl-D-alanine containing turnover products of the cell wall polymer murein [8].
• To test the effect of this altered peptide ligand (APL) on 3.L2 T cell function in vivo, a transgene expressing A72 in major histocompatibility complex II positive cells (A72tg) has been introduced into mice [9].
• The antibody is selective for L- vs. D-alanine and does not catalyze the hydrolysis of the acyl azide to an appreciable degree [10].
• The ampC beta-lactamase with a substrate specificity for cephalosporins showed no significant sequence homologies with beta-lactamases of the penicillinase type or with D-alanine carboxypeptidases [11].

Chemical compound and disease context of alanine

• Effects of sulfhydryl reagents on the binding and release of penicillin G by D-alanine carboxypeptidase IA of Escherichia coli [12].
• The mechanism of action of penicillin. Penicillin acylates the active site of Bacillus stearothermophilus D-alanine carboxypeptidase [13].
• Alanine at position 294 (Ala294) within the motif 3 consensus of Escherichia coli phenylalanyl-tRNA synthetase alpha subunit has previously been implicated as a determinant of amino acid specificity [14].
• Roles of Mycobacterium smegmatis D-alanine:D-alanine ligase and D-alanine racemase in the mechanisms of action of and resistance to the peptidoglycan inhibitor D-cycloserine [15].
• In water, the purified 26 000-Mr membrane-bound DD-peptidase of Streptomyces K15 hydrolyses the ester carbonyl donor Ac2-L-Lys-D-Ala-D-lactate (release of D-lactate) and the amide carbonyl donor Ac2-L-Lys-D-Ala-D-Ala (release of D-alanine) with accumulation of acyl- (Ac2-L-Lys-D-alanyl-)enzyme [16].

Biological context of alanine

• The two D-alanine carboxypeptidases showed significant homology around the active site [17].
• Several other structural modifications were shown to affect potency: substitution of D-alanine for glycine-2 reduced the potencies of dynorphin-(1--13) amide, -(1--11), and -(1--10); and methyl esterification of the COOH terminus enhanced the potencies of dynorphin-(1--12), -(1--10), -(1--9), -(1--8), and -(1--7) [18].
• Wild-type strains bearing additional copies of the dlt operon produced teichoic acids with higher amounts of D-alanine esters, bound cationic proteins less effectively and were less sensitive to antimicrobial peptides [19].
• Isolated membrane vesicles from Escherichia coli B grown on DL-alanine-glycerol carry out amino acid active transport coupled to D-alanine oxidation by a membrane-bound dehydrogenase [20].
• Using D-amino acid oxidase coupled with catalase for the deamination of D-alanine to pyruvic acid (a conversion unique to D-alanine), we were able to identify [14C]pyruvic acid in a [14C]alanine-labeled preparation of purified LPXTGase, which represents 27% of the amino acid composition [21].

Anatomical context of alanine

• Limited proteolysis of the penicillin-sensitive D-alanine carboxypeptidase purified from Bacillus subtilis membranes. Active water-soluble fragments generated by cleavage of a COOH-terminal membrane anchor [22].
• D-Alanine substitution of teichoic acids as a modulator of protein folding and stability at the cytoplasmic membrane/cell wall interface of Bacillus subtilis [23].
• Peroxisomes induced in Candida boidinii by methanol, oleic acid and D-alanine vary in metabolic function but share common integral membrane proteins [24].
• Staphylococcus aureus strains lacking D-alanine modifications of teichoic acids are highly susceptible to human neutrophil killing and are virulence attenuated in mice [25].
• Isomers harboring D-alanine in first position did not induce TNF-alpha secretion and influx of leukocytes [26].

Associations of alanine with other chemical compounds

• Both PBPs also catalyzed a model transpeptidase activity using glycine as a transpeptidation acceptor, and showed similar pH profiles and MgCl2 sensitivities for their D-alanine carboxypeptidase I activities [27].
• D-Amino acid transaminase, which catalyzes the synthesis of D-alanine and D-glutamate for the bacterial cell wall, is a candidate for the design of specific inhibitors that could be novel antimicrobial agents [28].
• It is demonstrated that: (a) Uptake of D-glucose by the membranes is inhibited by simultaneous flow of L- and D-alanine into the vesicles [29].
• Alkylation of cysteine 115 with sulfhydryl reagents has previously been shown to inhibit severely the D-alanine carboxypeptidase activity of PBP 5 [30].
• Surprisingly, the arginine-substituted protein was unable to catalyze D-alanine carboxypeptidase activity in vitro, which suggests that there is a substantial difference in the geometries of the peptide substrate and penicillin G within the active site of PBP 5 [31].
• Alanine showed the anticipated PPII propensity, but its conformational equilibrium was shifted towards helical conformations in Ac-Aib-Ala-Ala-OMe, indicating that Aib can induce helical conformations of neighboring residues positioned towards the C-terminal direction of the peptide [32].

Gene context of alanine

• Growth responses of pdxA, pdxB, and serC mutants to beta-hydroxypyruvate, D-alanine, and glycolate could also be reconciled with the proposed pathway [33].
• In dadX mutants, in which alanine racemase activity equals only 15% of that in wild-type cells grown in the absence of an inducer or catabolite repressor, the dad operon cannot be induced by D-alanine [34].
• Amino acid levels in D-alanine-administered mutant mice lacking D-amino acid oxidase [35].
• Consistent with an effect of L-Phe on the NMDAR glycine-binding site, L-Phe (1 mM) did not attenuate I(NMDA) in the presence of D-alanine (10 microM) [36].
• During D-alanine administration, DAO gene was expressed quickly in hepatopancreas with the increase of DAO activity [37].

Analytical, diagnostic and therapeutic context of alanine

• Slow processing of L-alanine to D-alanine was observed both by coupled enzymatic assays using D-amino acid oxidase and by high pressure liquid chromatography analysis employing an optically active chromophore (Marfey's reagent) [38].
• By introducing covalent affinity chromatography employing cephalosporins as ligands, milligram amounts of three high molecular weight PBPs (PBP 1 ab, Mr = 120,000; PBP 2b, Mr = 94,000; and PBP 4, Mr = 78,000) were obtained without any contamination of the major PBP 5, the D-alanine carboxypeptidase [39].
• The minimum inhibitory concentrations (MICs) for the peptide against Gram-negative species grown on enriched agar medium range from 1.56 to 12.5 micrograms/ml; MICs are increased to greater than 100 micrograms/ml when D-alanine is included in the medium, indicating that alanine racemase is, in fact, inhibited in sensitive species [40].
• DU-145 cells stably expressing wild-type and A654 EGFR were grown as xenografts in the s.c. space of athymic mice [41].
• CONCLUSIONS: The significant improvement with the D-alanine further supports the hypothesis of hypofunction of NMDA neurotransmission in schizophrenia and strengthens the proof of the principle that NMDA-enhancing treatment is a promising approach for the pharmacotherapy of schizophrenia [42].

References