Adenylate Deaminase Research Articles

Effects of different expression systems on characterization of adenylate deaminase from Aspergillus oryzae

Adenylate deaminase (AMPD) is an amino hydrolase that catalyzes the irreversible hydrolysis of adenosine monophosphate (AMP) to inosine monophosphate (IMP) and ammonia. In this study, the effect of different hosts on the enzymatic properties of AMPD from Aspergillus oryzae GX-08 was investigated and showed that Bacillus subtilis WB600 was more suitable for producing AMPD with a higher activity of 2540U/mL. After purification, the optimal temperature and pH of recombinant AMPD were 55°C and pH 6.0, respectively, and its activity was significantly enhanced by 10mM Fe3+ with an increase of 236%. More importantly, the recombinant AMPD specifically and effectively catalyzed the conversion between AMP and IMP, in which 10mL of crude AMPD achieved a conversion ratio of 76.4% after 40min. Therefore, B. subtilis WB600 provides a potential platform for producing AMPD with excellent catalytic ability and catalytic specificity.

Antacids’ side effect hyperuricaemia could be alleviated by long-term aerobic exercise via accelerating ATP turnover rate

Hyperuricemia is the term for an abnormally high serum uric acid level. Many factors contribute to hyperuricemia, however no definite correlation between proton pump inhibitors (PPIs) and hyperuricemia has been reported before. Physical exercise also decreases serum uric acid levels. However, the detailed biochemical-regulatory mechanisms remain unknown. Here we found that adenylate deaminase activities are much higher in hyperuricemia patients than in the healthy people. Therefore, the patients have higher levels of adenosine metabolites hypoxanthine and uric acid. Acid-inhibitory drugs (antacids) significantly increased serum uric acid level and may lead to gout in the hyperuricemia patient. Long-term aerobic exercise significantly increased serum phosphorus and decreased serum ATP and its metabolites, and therefore decreased serum uric acid. Antacids slow down the ATP turnover rate and result in serum uric acid elevation subsequently. While the long-term aerobic exercise decreases serum uric acid levels by accelerating ATP turnover rate. The results imply that long-term aerobic exercise may be a useful strategy to prevent and treat hyperuricaemia.

Metabolic Responses to Weight Lifting

Metabolic Responses to Weight Lifting

Overproduction, Purification and Characterization of Adenylate Deaminase from Aspergillus oryzae.

Adenylate deaminase (AMPD, EC 3.5.4.6) is an aminohydrolase that widely used in the food and medicine industries. In this study, the gene encoding Aspergillus oryzae AMPD was cloned and expressed in Escherichia coli. Induction with 0.75mM isopropyl β-D-l-thiogalactopyranoside resulted in an enzyme activity of 1773.9U/mL. Recombinant AMPD was purified to electrophoretic homogeneity using nickel affinity chromatography, and its molecular weight was calculated as 78.6kDa. Purified AMPD exhibited maximal activity at 35°C, pH6.0 and 30mMK+, with apparent K m and V max values of 2.7×10-4M and 77.5μmol/mg/min under these conditions. HPLC revealed that recombinant AMPD could effectively catalyse the synthesis of inosine-5'-monophosphate (IMP) with minimal by-products, indicating high specificity and suggesting that it could prove useful for IMP production.

Concise total synthesis of two marine natural nucleosides: trachycladines A and B.

We report the first total synthesis of trachycladines A (10 steps, 34.2% overall yield) and B (11 steps, 35.0% overall yield) by using 5-deoxy-1,2,3-tri-O-acetyl-β-D-ribofuranose as the starting material. The critical step was the SnCl4 assisted regio- and steroselective deprotection of perbenzylated 1-O-methyl-5-deoxyribofuranose. The enzyme adenylate deaminase (EC 3.5.4.6) was successfully applied to the chemoenzymatic synthesis of trachycladines B.

Muscle biopsy features in critical ill patients with 2009 influenza A (H1N1) virus infection

Higher serum creatine kinase (CK) levels in critically ill patients with a confirmed 2009 influenza A (H1N1) infection suggests a possible relationship between the H1N1 virus and muscle tissue. However, there have been no reports with an emphasis on muscle biopsies for patients infected with the H1N1 virus. The objective of this study was to investigate the histological characteristics of the muscle biopsies from critically ill patients with confirmed 2009 H1N1 infections. A series of ten patients with confirmed 2009 H1N1 infection, who presented increased serum CK levels, was analyzed. Histological study found small histochemical alterations in muscles fibers (mainly in NADH, SDH, COX, myophosphorylase, adenylate deaminase and PAS stains), and no histological changes were compatible with inflammatory myopathy. Although our critically ill patients had elevated CK levels, they exhibited few histological/histochemical abnormalities in their muscle biopsy samples; however, those alterations could be consistent with metabolic dysfunction associated with influenza H1N1 infection.

Mechanism of ATP loss in nonoxidative contracting muscle

The transition from rest to intense exercise is a challenge to cellular energetics ([11][1], [13][2], [15][3]). The metabolic fuels, i.e., the sources of ATP to sustain muscular contraction, are creatine phosphate and glycogen. Two anaerobic metabolic paths, leading to ATP generation, are catalyzed

A 57-gene expression signature in B-cell chronic lymphocytic leukemia

B-CLL is the most frequent type of leukemia in the Western countries. The disease, common among the elderly, follows a variable course in terms of survival time and symptoms. There is evidence that the accumulation of lymphocytes in peripheral blood and bone marrow is due to a cell resistance to apoptosis rather than to highly proliferative cells. Genetic mechanisms that lead to the development and progression of disease are mainly unknown, although a number of prognostically and diagnostically important genetic markers have been identified. The aim of this study is to investigate the gene expression profile, by a specific chip for microarray analysis, in B-CLL lymphocytes with regard to factors involved in apoptosis cascade, signal transduction, purine metabolism enzymes, interleukin expression, enzymes involved in the responses to oxidative stress. We found relevant results in a set of 19 of the 57 genes considered. IMP dehydrogenase, adenine phosphoribosyltransferase, adenylosuccinate lyase, adenylate kinase, ADORA1, G-protein-coupled receptor kinase 6, Bcl-2-like 1 isoform 2, caspase 6, and 8 were found underexpressed; while ADORA3, Gars-Airs-Gart, adenylate kinase 3, adenylate deaminase, NMN adenylyltransferase, CD26, CD38, interleukins 18 and 4 were found overexpressed. The microarray technique is a powerful method for identification of potential important diagnostic and prognostic markers, besides giving prominence to genes candidate for further studies.

Effects of alcohol–kola nut interactions on brain glucose oxidase, glutamine synthase, and adenylate deaminase activities in Wistar rats

The effects of alcohol–kola nut interactions on activites of whole brain glucose oxidase, glutamine synthetase, and adenylate deaminase were examined in Wistar rats. Thirty Wistar albino rats were divided into six groups. Control group (1) received a placebo (4 mL of distilled water). Groups 2–6 were treated for a 21-day period with either 10% (v/v) alcohol, kola nut, caffeine, alcohol + kola nut, or alcohol + caffeine at 50 mg per kg in a total volume of 4 mL vehicle via gastric intubation, respectively. One day after the final treatment, the whole brain was harvested and processed to examine for several biochemical parameters, including activities of glucose oxidase, adenylate deaminase, and glutamine synthetase. Results showed that alcohol–kola nut interaction decreased the activities of glucose oxidase, adenylate deaminase, and glutamine synthetase in whole brain, suggesting inhibition of glutamine synthesis, decreased energy (ATP) production, ionic transport and decreased neuronal processes. Data indicates that alcohol–kola nut or alcohol–caffeine interactions modify neuronal processes in rat brain; however, the clinical importance of this is not known.

Two-step Enzymatic Synthesis of Guanine Arabinoside

The chemical synthesis of Guanine arabinoside (ara-G) is extremely complex, time-consuming, and seriously polluted. A two-step enzymatic synthesis process was developed to acquire ara-G easily. 2,6-Diaminopurine arabinoside (ara-DA) was first synthesized with purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase produced by Enterobacter aerogenes DGW-07. The conversion yield of ara-DA could reach above 90% when the reaction liquid contained 30 mmol·L −1 uracil arabinoside as arabinose donor, 10 mmol·L −1 2,6-diaminopurine as arabinose acceptor in pH 7.0 20 mmol·L −1 phosphate buffer, and reacted at 60°C for 48h. Then, ara-DA was effectively transformed into ara-G with adenylate deaminase produced by Aspergillus oryzae DAW-01. The total process had no complex separation and purification.

ChemInform Abstract: 2′,3′‐Isopropylidene Group, a Molecular Scaffold to Study the Activity of Adenosine and Adenylate Deaminase on Adenosine Analogues Modified in the Ribose Moiety

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Activity of Adenosine Deaminase and Adenylate Deaminase on Adenosine and 2', 3'-Isopropylidene Adenosine: Role of the Protecting Group at Different pH Values

The deamination rate of 2',3'-isopropylidene adenosine catalyzed by adenosine deaminase (ADA) from calf intestine and adenylate deaminase (AMPDA) from Aspergillus species has been evaluated and compared with that of the enzymatic reactions of adenosine, to elucidate the influence of the protecting group on ezyme activity.

2′,3′-Isopropylidene Group, A Molecular Scaffold to Study the Activity of Adenosine and Adenylate Deaminase on Adenosine Analogues Modified in the Ribose Moiety

2 ′,3 ′-Isopropylidene group can be used as a molecular scaffold for the introduction of modifications at 5 ′ and 1 ′ positions of adenosine and these modified nucleosides are used to evaluate the biocatalytic activity of adenosine and adenylate deaminase.

Facile and Rapid Access to Inosine Puromycin Analogues through the Use of Adenylate Deaminase

To study the ribosomal peptidyl transfer, puromycin analogues are of interest in which adenine has been replaced by hypoxanthine. We synthesized inosine puromycin analogues from 3'-azidodeoxyadenosine derivatives using adenylate deaminase for the quantitative transformation of the N-heterocycle. The amino acid coupling was carried out under Staudinger-Vilarrasa conditions in 94% yield starting from the protected and in 82% using the unprotected azide, thus, in the presence of two hydroxyls and a lactam function.

Deamination of 2′,3′-O-Isopropylideneadenosine-5′- Carboxylic Acid Catalyzed by Adenosine Deaminase (ADA) and Adenylate Deaminase (AMPDA): Influence of Substrate Ionization on the Activity of the Enzymes

Adenosine deaminase (ADA) and adenylate deaminase (AMPDA) catalyze the deamination of 2 ′,3 ′-O-isopropylideneadenosine-5′-carboxylic acid to the corresponding inosine derivative and dependence of the rate of enzymatic reaction on the ionization degree of the substrate has been studied at different pH values.

Synthesis of Modified Purine Nucleosides and Related Compounds Mediated by Adenosine Deaminase (ADA) and Adenylate Deaminase (AMPDA)

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of Modified Purine Nucleosides and Related Compounds Mediated by Adenosine Deaminase (ADA) and Adenylate Deaminase (AMPDA)

Adenosine deaminase (ADA) and adenylic acid deaminase (AMPDA) are enzymes that catalyze the hydrolytic deamination of various purine nucleosides. In light of recent reports, ADA and AMPDA may be considered as valuable biocatalysts in nucleoside chemistry. Here, they can find many synthetic applications in the transformation of purine nucleosides that are modified in the base or the ribose moiety. Their use can be extended to carbocyclonucleosides or acyclonucleosides as well.

Evaluation of neuromuscular symptoms in UK Gulf War veterans

To determine whether Gulf War veterans with neuromuscular symptoms that included weakness and fatigue had either 1) objective correlates for muscle weakness or fatigue; or 2) any etiologic explanation for such symptoms; and if so, 3) whether such objective measures or etiologic mechanisms were specific to Gulf War service. Forty-nine ill Gulf War veterans with more than four neuromuscular symptoms (Gulf-ill) were compared with 26 Gulf-well veterans, 13 symptomatic Bosnian veterans (Bosnia-ill), and 22 symptomatic troops who were not deployed to the Gulf (Era-ill). Quantitative myometry was used to objectively measure weakness and fatigue. Subjects had an ischemic forearm exercise test, a subanaerobic bicycle exercise test, and a muscle biopsy. Quantitative strength and fatigue measures did not correlate with self-perception of weakness or fatigue for any of our groups. No specific muscle biopsy abnormalities were found. There was no defect of adenylate deaminase or glycogenolysis found. Gulf-ill subjects did find the subanaerobic bicycle exercise more effortful and generated significantly higher plasma lactate concentrations compared with Gulf-well subjects. Because complaints of weakness and fatigue in unwell servicemen do not correlate with actual weakness or fatigue, explanations for these symptoms must lie outside of the neuromuscular system. Increased lactate production during subanaerobic bicycle exercise reflects mitochondrial inefficiency, but it is unclear whether this reflects mitochondrial damage sustained during Gulf War service or inactivity secondary to ill health.

Activity of Adenosine Deaminase (ADA) and Adenylate Deaminase (AMPDA) Towards 6‐Chloropurine Nucleosides Modified in the Ribose Moiety

AbstractThe enzymes adenosine deaminase (ADA) and adenylate deaminase (AMPDA) are able to catalyze the hydrolytic dechlorination of 6‐chloropurine riboside and the corresponding 2′,3′‐O‐isopropylidene derivative, but show no activity towards the 3,4‐O‐isopropylidene‐1‐methylriboside of 6‐chloropurine and adenine. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Stereoselective adenylate deaminase (5 ′-adenylic acid deaminase, AMPDA)-catalyzed deamination of 5 ′-alkyl substituted adenosines: a comparison with the action of adenosine deaminase (ADA)

The enzymes adenylate deaminase (AMPDA) and adenosine deaminase (ADA) are able to catalyze the stereoselective hydrolytic deamination of (5 ′ R, S)-methyl-2 ′,3 ′-isopropylidene adenosine, but the 5 ′-butyl analog is a substrate only for AMPDA, which stereospecifically converts the (5 ′ S)-isomer to the corresponding inosine derivative.