scholarly journals Regulation of the dauBAR operon and characterization of d-amino acid dehydrogenase DauA in arginine and lysine catabolism of Pseudomonas aeruginosa PAO1

Microbiology ◽  
2010 ◽  
Vol 156 (1) ◽  
pp. 60-71 ◽  
Author(s):  
Congran Li ◽  
Xiangyu Yao ◽  
Chung-Dar Lu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Mutation Analysis ◽  
Regulatory Region ◽  
Mobility Shift ◽  
Signal Molecule ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
Activity Measurements

A unique d-to-l racemization of arginine by coupled arginine dehydrogenases DauA and DauB encoded by the dauBAR operon has been recently reported as a prerequisite for d-arginine utilization as the sole source of carbon and nitrogen through l-arginine catabolic pathways in P. aeruginosa. In this study, enzymic properties of the catabolic FAD-dependent d-amino acid dehydrogenase DauA and the physiological functions of the dauBAR operon were further characterized with other d-amino acids. These results establish DauA as a d-amino acid dehydrogenase of broad substrate specificity, with d-Arg and d-Lys as the two most effective substrates, based on the kinetic parameters. In addition, expression of dauBAR is specifically induced by exogenous d-Arg and d-Lys, and mutations in the dauBAR operon affect utilization of these two amino acids alone. The function of DauR as a repressor in the control of the dauBAR operon was demonstrated by dauB promoter activity measurements in vivo and mobility shift assays with purified His-tagged protein in vitro. The potential effect of 2-ketoarginine (2-KA) derived from d-Arg deamination by DauA as a signal molecule in dauBAR induction was first revealed by mutation analysis and further supported by its in vitro effect on alleviation of DauR–DNA interactions. Through sequence analysis, putative DauR operators were identified and confirmed by mutation analysis. Induction of the dauBAR operon to the maximal level was found to require the l-arginine-responsive regulator ArgR, as supported by the loss of inductive effect by l-Arg on dauBAR expression in the argR mutant and binding of purified ArgR to the dauB regulatory region in vitro. In summary, this study establishes that optimal induction of the dauBAR operon requires relief of DauR repression by 2-KA and activation of ArgR by l-Arg as a result of d-Arg racemization by the encoded DauA and DauB.

scholarly journals Creation of a Broad-Range and Highly Stereoselectived-Amino Acid Dehydrogenase for the One-Step Synthesis ofd-Amino Acids

2006 ◽  
Vol 128 (33) ◽  
pp. 10923-10929 ◽  
Author(s):  
Kavitha Vedha-Peters ◽  
Manjula Gunawardana ◽  
J. David Rozzell ◽  
Scott J. Novick
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
One Step ◽  
The One

Development of β-Amino Acid Dehydrogenase for the Synthesis of β-Amino Acids via Reductive Amination of β-Keto Acids

ACS Catalysis ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 2220-2224 ◽  
Author(s):  
Dalong Zhang ◽  
Xi Chen ◽  
Rui Zhang ◽  
Peiyuan Yao ◽  
Qiaqing Wu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Reductive Amination ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
Keto Acids

scholarly journals Functional characterization of the dguRABC locus for d-Glu and d-Gln utilization in Pseudomonas aeruginosa PAO1

Microbiology ◽  
2014 ◽  
Vol 160 (10) ◽  
pp. 2331-2340 ◽  
Author(s):  
Weiqing He ◽  
Guoqing Li ◽  
Chun-Kai Yang ◽  
Chung-Dar Lu
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Gene Knockout ◽  
Functional Characterization ◽  
Transcriptional Activator ◽  
Sequence Motif ◽  
Acid Uptake ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
Activity Measurements

d-Glu, an essential component of peptidoglycans, can be utilized as a carbon and nitrogen source by Pseudomonas aeruginosa. DNA microarrays were employed to identify genes involved in d-Glu catabolism. Through gene knockout and growth phenotype analysis, the divergent dguR–dguABC (d-Glu utilization) gene cluster was shown to participate in d-Glu and d-Gln catabolism and regulation. Growth of the dguR and dguA mutants was abolished completely on d-Glu or retarded on d-Gln as the sole source of carbon and/or nitrogen. The dguA gene encoded a FAD-dependent d-amino acid dehydrogenase with d-Glu as its preferred substrate, and its promoter was specifically induced by exogenous d-Glu and d-Gln. The function of DguR as a transcriptional activator of the dguABC operon was demonstrated by promoter activity measurements in vivo and by mobility shift assays with purified His-tagged DguR in vitro. Although the DNA-binding activity of DguR did not require d-Glu, the presence of d-Glu, but not d-Gln, in the binding reaction was found to stabilize a preferred nucleoprotein complex. The presence of a putative DguR operator was revealed by in silica analysis of the dguR–dguA intergenic regions among Pseudomonas spp. and binding of DguR to a highly conserved 19 bp sequence motif was further demonstrated. The dguB gene encodes a putative enamine/imine deaminase of the RidA family, but its role in d-Glu catabolism remains to be determined. Whilst a lesion in dguC encoding a periplasmic solute binding protein only affected growth on d-Glu slightly, expression of the previously characterized AatJMQP transporter for acidic l-amino acid uptake was found inducible by d-Glu and essential for d-Glu utilization. In summary, the findings of this study supported DguA as a new member of the FAD-dependent d-amino acid dehydrogenase family, and DguR as a d-Glu sensor and transcriptional activator of the dguA promoter.

scholarly journals Structure-Based Engineering of an Artificially Generated NADP+-Dependent d-Amino Acid Dehydrogenase

2017 ◽  
Vol 83 (11) ◽  
Author(s):  
Junji Hayashi ◽  
Tomonari Seto ◽  
Hironaga Akita ◽  
Masahiro Watanabe ◽  
Tamotsu Hoshino ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Specific Activity ◽  
High Specific Activity ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
High Catalytic Activity ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase

ABSTRACT A stable NADP+-dependent d-amino acid dehydrogenase (DAADH) was recently created from Ureibacillus thermosphaericus meso-diaminopimelate dehydrogenase through site-directed mutagenesis. To produce a novel DAADH mutant with different substrate specificity, the crystal structure of apo-DAADH was determined at a resolution of 1.78 Å, and the amino acid residues responsible for the substrate specificity were evaluated using additional site-directed mutagenesis. By introducing a single D94A mutation, the enzyme's substrate specificity was dramatically altered; the mutant utilized d-phenylalanine as the most preferable substrate for oxidative deamination and had a specific activity of 5.33 μmol/min/mg at 50°C, which was 54-fold higher than that of the parent DAADH. In addition, the specific activities of the mutant toward d-leucine, d-norleucine, d-methionine, d-isoleucine, and d-tryptophan were much higher (6 to 25 times) than those of the parent enzyme. For reductive amination, the D94A mutant exhibited extremely high specific activity with phenylpyruvate (16.1 μmol/min/mg at 50°C). The structures of the D94A-Y224F double mutant in complex with NADP+ and in complex with both NADPH and 2-keto-6-aminocapronic acid (lysine oxo-analogue) were then determined at resolutions of 1.59 Å and 1.74 Å, respectively. The phenylpyruvate-binding model suggests that the D94A mutation prevents the substrate phenyl group from sterically clashing with the side chain of Asp94. A structural comparison suggests that both the enlarged substrate-binding pocket and enhanced hydrophobicity of the pocket are mainly responsible for the high reactivity of the D94A mutant toward the hydrophobic d-amino acids with bulky side chains. IMPORTANCE In recent years, the potential uses for d-amino acids as source materials for the industrial production of medicines, seasonings, and agrochemicals have been growing. To date, several methods have been used for the production of d-amino acids, but all include tedious steps. The use of NAD(P)+-dependent d-amino acid dehydrogenase (DAADH) makes single-step production of d-amino acids from oxo-acid analogs and ammonia possible. We recently succeeded in creating a stable DAADH and demonstrated that it is applicable for one-step synthesis of d-amino acids, such as d-leucine and d-isoleucine. As the next step, the creation of an enzyme exhibiting different substrate specificity and higher catalytic efficiency is a key to the further development of d-amino acid production. In this study, we succeeded in creating a novel mutant exhibiting extremely high catalytic activity for phenylpyruvate amination. Structural insight into the mutant will be useful for further improvement of DAADHs.

scholarly journals Interference by branched-chain amino acids in the assay of alanine with alanine dehydrogenase

1978 ◽  
Vol 174 (3) ◽  
pp. 1079-1082 ◽  
Author(s):  
P Lund ◽  
G Baverel
Keyword(s):  
Amino Acids ◽  
Bacillus Subtilis ◽  
Amino Acid ◽  
Dehydrogenase Activity ◽  
Branched Chain Amino Acids ◽  
Acid Dehydrogenase ◽  
Alanine Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
Branched Chain Amino Acid ◽  
Branched Chain

Commercial preparations of alanine dehydrogenase from Bacillus subtilis are contaminated to varying extents with activity towards branched-chain amino acids. The Km values for these amino acids are of the same order as for L-alanine (about 10(-3)M). The branched-chain amino acid dehydrogenase activity is lost on dialysis for 2–4h against water or 2mM-EDTA.

Enzymatic synthesis of cyclic amino acids by N-methyl-l-amino acid dehydrogenase from Pseudomonas putida

2006 ◽  
Vol 17 (12) ◽  
pp. 1775-1779 ◽  
Author(s):  
Mari Yasuda ◽  
Makoto Ueda ◽  
Hisashi Muramatsu ◽  
Hisaaki Mihara ◽  
Nobuyoshi Esaki
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Pseudomonas Putida ◽  
Enzymatic Synthesis ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
Cyclic Amino Acids

scholarly journals FRUCTOSE-AMINO ACIDS IN LIVER: STIMULI OF AMINO ACID INCORPORATION IN VITRO

1955 ◽  
Vol 215 (1) ◽  
pp. 111-124 ◽  
Author(s):  
Henry Borsook ◽  
Adolph Abrams ◽  
Peter H. Lowy
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

scholarly journals Transdermal Delivery Systems for Ibuprofen and Ibuprofen Modified with Amino Acids Alkyl Esters Based on Bacterial Cellulose

2021 ◽  
Vol 22 (12) ◽  
pp. 6252
Author(s):  
Paula Ossowicz-Rupniewska ◽  
Rafał Rakoczy ◽  
Anna Nowak ◽  
Maciej Konopacki ◽  
Joanna Klebeko ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bacterial Cellulose ◽  
Acid Ester ◽  
Active Pharmaceutical Ingredient ◽  
Amino Acid Ester ◽  
Isopropyl Ester ◽  
Isopropyl Esters ◽  
Transdermal Application

The potential of bacterial cellulose as a carrier for the transport of ibuprofen (a typical example of non-steroidal anti-inflammatory drugs) through the skin was investigated. Ibuprofen and its amino acid ester salts-loaded BC membranes were prepared through a simple methodology and characterized in terms of structure and morphology. Two salts of amino acid isopropyl esters were used in the research, namely L-valine isopropyl ester ibuprofenate ([ValOiPr][IBU]) and L-leucine isopropyl ester ibuprofenate ([LeuOiPr][IBU]). [LeuOiPr][IBU] is a new compound; therefore, it has been fully characterized and its identity confirmed. For all membranes obtained the surface morphology, tensile mechanical properties, active compound dissolution assays, and permeation and skin accumulation studies of API (active pharmaceutical ingredient) were determined. The obtained membranes were very homogeneous. In vitro diffusion studies with Franz cells were conducted using pig epidermal membranes, and showed that the incorporation of ibuprofen in BC membranes provided lower permeation rates to those obtained with amino acids ester salts of ibuprofen. This release profile together with the ease of application and the simple preparation and assembly of the drug-loaded membranes indicates the enormous potentialities of using BC membranes for transdermal application of ibuprofen in the form of amino acid ester salts.

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