Adenosine Mono Research Articles

How Does Mg2+(aq) Interact with ATP(aq)? Biomolecular Structure through the Lens of Liquid-Jet Photoemission Spectroscopy.

Liquid-jet photoemission spectroscopy (LJ-PES) allows for a direct probing of electronic structure in aqueous solutions. We show the applicability of the approach to biomolecules in a complex environment, exploring site-specific information on the interaction of adenosine triphosphate in the aqueous phase (ATP(aq)) with magnesium (Mg2+(aq)), highlighting the synergy brought about by the simultaneous analysis of different regions in the photoelectron spectrum. In particular, we demonstrate intermolecular Coulombic decay (ICD) spectroscopy as a new and powerful addition to the arsenal of techniques for biomolecular structure investigation. We apply LJ-PES assisted by electronic-structure calculations to study ATP(aq) solutions with and without dissolved Mg2+. Valence photoelectron data reveal spectral changes in the phosphate and adenine features of ATP(aq) due to interactions with the divalent cation. Chemical shifts in Mg 2p, Mg 2s, P 2p, and P 2s core-level spectra as a function of the Mg2+/ATP concentration ratio are correlated to the formation of [Mg(ATP) 2]6-(aq), [MgATP]2-(aq), and [Mg2ATP](aq) complexes, demonstrating the element sensitivity of the technique to Mg2+-phosphate interactions. The most direct probe of the intermolecular interactions between ATP(aq) and Mg2+(aq) is delivered by the emerging ICD electrons following ionization of Mg 1s electrons. ICD spectra are shown to sensitively probe ligand exchange in the Mg2+-ATP(aq) coordination environment. In addition, we report and compare P 2s data from ATP(aq) and adenosine mono- and diphosphate (AMP(aq) and ADP(aq), respectively) solutions, probing the electronic structure of the phosphate chain and the local environment of individual phosphate units in ATP(aq). Our results provide a comprehensive view of the electronic structure of ATP(aq) and Mg2+-ATP(aq) complexes relevant to phosphorylation and dephosphorylation reactions that are central to bioenergetics in living organisms.

In situ enzymatic control of colloidal phoresis and catalysis through hydrolysis of ATP.

The ability to sense chemical gradients and respond with directional motility and chemical activity is a defining feature of complex living systems. There is a strong interest among scientists to design synthetic systems that emulate these properties. Here, we realize and control such behaviors in a synthetic system by tailoring multivalent interactions of adenosine nucleotides with catalytic microbeads. We first show that multivalent interactions of the bead with gradients of adenosine mono-, di- and trinucleotides (AM/D/TP) control both the phoretic motion and a proton-transfer catalytic reaction, and find that both effects are diminished greatly with increasing valence of phosphates. We exploit this behavior by using enzymatic hydrolysis of ATP to AMP, which downregulates multivalent interactivity in situ. This produces a sudden increase in transport of the catalytic microbeads (a phoretic jump), which is accompanied by increased catalytic activity. Finally, we show how this enzymatic activity can be systematically tuned, leading to simultaneous in situ spatial and temporal control of the location of the microbeads, as well as the products of the reaction that they catalyze. These findings open up new avenues for utilizing multivalent interaction-mediated programming of complex chemo-mechanical behaviors into active systems.

Ultra‐Small ATP‐Decorated Gold Nanoparticles for Targeting Amyloid Fibrils in Neurodegenerative Diseases

AbstractUltrafine Gold nanoparticles (Au NPs) functionalized with various biomolecules constitute an alternative to antibodies as anti‐amyloidogenic agents. However, generating stable ultrafine Au NPs with high surface activity is challenging. Here, the capacity of phosphate groups in biomolecules is used to stabilize Au NPs. The characteristics of Au NPs decorated with adenosine mono‐, di‐, and tri‐phosphate are compared as well as adenosine and peptide nucleic acid‐containing adenosine as controls. Among them, ATP‐Au NPs are found to be superior having small size (2–4 nm) and stability (for several months) when analysed by spectroscopy and electron microscopy. Spectroscopy analysis also revealed that each ATP‐stabilized Au NP is decorated with 7–8 molecules of ATP. ThT binding analysis and TEM imaging showed that the ATP‐Au NPs efficiently prevented amyloid fibril formation in vitro by Aβ‐42, α‐Synuclein as well as by the Glucosylceramide metabolite, and disaggregated their pre‐formed fibrils. NMR analysis revealed the interaction of the ATP‐Au NPs with the amyloid fibrils. The ATP‐Au NPs are safe toward cultured SH‐SY5Y cells and when co‐incubated with α‐Synuclein amyloids inhibited their cytotoxicity and readily enter the cells to inhibit formation of amyloid fibrils within them. The results indicates the pharmacological potentials of ATP decorated Au NPs.

Autophagy modulation in primary culture of porcine satellite cells

Autophagy is a lysosomal degradation pathway with a role in the turnover of cell components via self-digestion. Over the past decade, it has been recognised as an essential process to maintain cellular and energy homeostasis. Nevertheless, little attention has been paid to this process in farm animals. In pigs, the role of autophagy in skeletal muscle homeostasis and more specifically on the formation of multinucleated muscle fibres needs to be determined. Primary culture of satellite cells, the resident muscle stem cells, is an appropriate model to investigate macroautophagy (hereafter autophagy), the main autophagy process. The objective of the current study was to evaluate tools to monitor autophagy in this cell model and to specify the role of autophagy on cell differentiation. Samples of longissimus muscle were collected from 3- to 4-day-old piglets. After isolation, satellite cells were plated in growth medium, allowed to proliferate up to 80% confluence and then placed in an appropriate culture medium to differentiate into myotubes. Cells were explored from day 0 to day 3 of differentiation. Autophagy-related proteins and Adenosine Mono Phosphate-activated protein kinase (AMPK), a major sensor for cell energy, were detected by Western blotting. Expression of genes related to autophagy were also quantified by qPCR. The Microtubule-associated protein 1 light-chain 3β forms ratio increased during cell differentiation whereas phosphatidylinositol 3-kinase and sequestosome 1 proteins decreased significantly. Mitochondrial protein expression also decreased significantly with satellite cell differentiation. Then, cell treatment with an inhibitor of autophagy flux, Bafilomycin A1, confirmed that autophagy was activated during the conversion of myoblasts into myotubes along with AMPK activation in our satellite cell culture model. In conclusion, we provided tools for porcine autophagy investigation in tissues or cells and demonstrated that basal autophagy and energy metabolism are concomitantly modulated during porcine myogenesis in vitro.

Tag‐Free Antibody Modification Mediated by Lipoic Acid Ligase A: Application to Antibody‐Drug Conjugates Production

AbstractEnzymatic modifications of proteins are of great interest in the pharmaceutical industry as it enables the production of homogeneous protein conjugates such as antibody‐drug conjugates, which are considered to be promising for cancer medicine. Several biotechnology companies have established proprietary conjugation technologies using specific enzymes. Most enzymatic modifications require the use of tags and enzyme‐recognition moieties. Therefore, site‐specific and “tag‐free” modifications are required to avoid the time‐consuming process of installing tags on proteins. Lipoic acid ligase A (LplA), is a recently reported enzyme having the potential to be used for the site‐specific modification of native antibodies without requiring a tag moiety. In this manuscript, investigations focused on the optimization of this enzymatic modification applied to antibody‐drug conjugates (ADCs) production. First, an analysis of the pH dependency was performed. Next, the effects of excess adenosine mono‐ and di‐phosphate were also examined to show that these by‐products from LplA modification did not have a significant impact on inhibiting the reaction efficiency. Furthermore, ADC syntheses by LplA‐mediated tag‐free modification followed by click reaction were achieved. To the best of our knowledge, this is the first example of actual ADC synthesis produced by LplA modification of tag‐free antibodies. A stability assessment of the resulting ADCs indicated that this enzymatic approach is a promising tool for installing biorthogonal groups to native antibodies for the next generation of ADC manufacturing.

Regulation and Role of AMP-Activated Protein Kinase at the Cellular Level and Relevance to Diabetes Mellitus

Adenosine Mono phosphate -activated protein kinase (AMPK) is a metabolic master switch that senses the cellular AMP levels. However, it is now also regarded as a nutrient-sensing enzyme due to its ability to detect glucose deprivation inside the cell. Under conditions of energy deprivation, AMPK is activated, which in turn switches on all the energy-producing metabolic pathways, while switching off energy-consuming metabolic pathways and cellular processes. There is a growing interest in AMPK due to its role in a wide array of pathological processes including diabetes mellitus. It is the therapeutic target of one of the most commonly prescribed classes of antidiabetic drugs, namely the biguanides such as metformin. The current article presents a review of AMPK structure, triggers, and mechanisms of its activation as well as its role in cell metabolism, mitochondrial homeostasis, autophagy, and cell proliferation. It also briefly addresses the relevance of AMPK to pathogenesis and management of diabetes mellitus.

Serum Adiponectin as a Diagnostic Marker of Nephropathy among Patients with Type 2 Diabetes Mellitus: A Cross-sectional Study

Introduction: Diabetic Nephropathy (DN) is the leading cause of End-Stage Renal Disease (ESRD) among Type 2 Diabetes Mellitus (T2DM) patients and it is a diagnosed by laboratory investigation like albuminuria. Albuminuria is a conventional and not a sensitive, specific marker for diagnosis of nephropathy. Additionally some of the patients shows advanced renal pathological changes without albuminuria and some of the patients with microalbuminuria revert back to normoalbuminuria. However, there is need for early detection, sensitive and specific marker for nephropathy. Serum adiponectin is an adipocytokine synthesised from adipose tissue, liver, kidney, heart, salivary glands. This has physiological properties like antidiabetic, antioxidative and anti-inflammatory properties beneficial for particularly in patient with T2DM. Adiponectin activates Adenosine Mono Phosphate (AMP) Kinase and Nicotinamide Adenine Dinucleotide Phosphate (NADPH) pathways results in improve insulin sensitivity and preventing albumin excretion in urine. Increased adiponectin levels are beneficial to patients with T2DM and its complications. Aim: To determine serum adiponectin levels for the prediction of early onset of nephropathy in patients with T2DM. Materials and Methods: This cross-sectional study was conducted from March 2018 to May 2019 at the Department of Biochemistry and Endocrine at the Basaveshwara Medical University Hospital and Research Centre in Karnataka, India, with a total of 120 subjects. Out of the 120 subjects, 80 were T2DM subjects and 40 were age, gender and BMI matched controls (group 1). Eighty T2DM subjects were further categorised into two groups based on urinary Albumin-to-Creatinine Ratio (ACR) levels, such as 40 T2DM with normoalbuminuria [(Group 2), Urine ACR: <30 mg/g], and 40 T2DM with microalbuminuria, [(Group 3) urinary ACR: 30-299 mg/g]. Comparisons were made between groups based on socio-demographic and clinical parameters. Pearson's correlation was used to test the relationship between estimated Glomerular Filtration Rates (eGFR), Glycated Haemoglobin (HbA1c), urine ACR, and serum adiponectin. The Receiver Operating Characteristic (ROC) curve was used to test the sensitivity and specificity of a marker for nephropathy. The Statistical Package for the Social Sciences (SPSS) version 20.0 and Medcalc Software were used to analyse data. Results: The mean values of serum adiponectin were significantly higher in patients with T2DM 11.92±3.86 when compared to controls 3.84±1.98. The serum adiponectin had a significantly very high positive correlation with HbA1c, urinary ACR r=0.726, 0.642, p-value=0.0001 and also a significantly very high negative correlation with estimated glomerular filtration rate, r =-0.399, p-value=0.0001 was observed. In ROC analysis serum adiponectin was found to be proportionately elevated in T2DM with normoalbuminuria and it was statistically significant, with a sensitivity of 92.5% and specificity of 87.50, p-value=0.0001. The urinary ACR also has shown significance with low sensitivity of 62.5% and specificity of 80%, p-value=0.0250. Conclusion: The serum adiponectin might be a sensitive and specific marker to predict the early onset of nephropathy in T2DM patients and therefore can be used as a diagnostic marker for DN. These concentrations were positively correlated with urinary ACR and negatively correlated with eGFR.

Ageing process and policosanol effects

The fundamental concepts of the aging process are exposed: Its dimension as a health problem, aspects related to its repercussion from the social point of view, and Its influence on aspects that can affect the normal development of contemporary society. The roles of genetics, cellular and biochemical processes that concur in the development of aging is analyzed, making special reference to the role of Adenosine Mono Phosphate Kinase [AMPK]. activation in the regulation of the aging process and the participation of mechanisms for its activation. It is concluded that Policosanol is a medicament of natural origin that could be proposed as candidate to be used for a healthy aging, based on the results of various investigations in experimental models and data obtained from different clinical trials.

Characterization of polyphosphate kinases for the synthesis of GSH with ATP regeneration from AMP

Polyphosphate kinase (PPK) is important for industrial processes involving ATP regeneration. While a variety of methods have been reported for regenerating ATP from ADP, few have explored enzyme catalyzed ATP regeneration from cheaper and stable AMP. In this work, PPKs from different sources were expressed and their catalytic activity were tested at different reaction temperatures, reaction pH and with different polyphosphate (polyPn) types. The ATP regeneration system for glutathione (GSH) synthesis was established using a single PPK capable of phosphorylating AMP to synthesize ATP from AMP and short chain polyPn. GSH yield was obtained using adenosine mono-, di- and triphosphates, which confirmed the flexibility of our constructed ATP regeneration system coupled with GSH synthesis via bifunctional GSH synthase. Finally, optimization of the GSH synthesis yielded conversion value above 80 %. Overall, these results illustrate that PPK is suitable for a broader range of substrates than previously expected, and has great untapped potential for applications involving ATP regeneration.

Does Metformin Satisfy as an Option for Host-Directed Therapy in COVID-19?

Metformin is a dimethyl biguanide known for its anti-hyperglycemic effects since 1922 and, thus, has been used in the treatment of Type 2 Diabetes Mellitus. Apart from this, its function as an anti-inflammatory, anti-oxidant, anti-thrombotic, and anti-microbial agent has also been studied largely. Its effect via inhibition of respiratory complex 1 and glycerol-3-phosphate dehydrogenase (GPD2) in the mitochondria and inhibition of the mammalian target of rapamycin complex 1 (mTORC1) and activation of Adenosine Mono Phosphate dependent kinase (AMPK) in the cytoplasm are its already known mechanisms of action. With the newer proposed effects on endosome/ lysosome regulation via Na+/H+ exchangers and V-ATPase, thereby affecting autophagy, coupled with its use in ARDS owing to its immunomodulatory effects and anti-viral action, the use of metformin against the novel Coronavirus is hypothesized.

Prebiotically-relevant low polyion multivalency can improve functionality of membraneless compartments

Multivalent polyions can undergo complex coacervation, producing membraneless compartments that accumulate ribozymes and enhance catalysis, and offering a mechanism for functional prebiotic compartmentalization in the origins of life. Here, we evaluate the impact of lower, more prebiotically-relevant, polyion multivalency on the functional performance of coacervates as compartments. Positively and negatively charged homopeptides with 1–100 residues and adenosine mono-, di-, and triphosphate nucleotides are used as model polyions. Polycation/polyanion pairs are tested for coacervation, and resulting membraneless compartments are analyzed for salt resistance, ability to provide a distinct internal microenvironment (apparent local pH, RNA partitioning), and effect on RNA structure formation. We find that coacervates formed by phase separation of the shorter polyions more effectively generated distinct pH microenvironments, accumulated RNA, and preserved duplexes than those formed by longer polyions. Hence, coacervates formed by reduced multivalency polyions are not only viable as functional compartments for prebiotic chemistries, they can outperform higher molecular weight analogues.

Quantification of adenosine Mono-, Di- and triphosphate from royal jelly using liquid chromatography - Tandem mass spectrometry.

Nucleotides are composed of nitrogen bases, ribose units and phosphate groups. Adenine (Ade), adenosine monophosphate (AMP), adenosine diphosphate (ADP) and adenosine triphosphate (ATP) all play important roles in physiological metabolism. Royal jelly, a secretion produced by worker bees, contains a variety of natural ingredients and several studies have shown that royal jelly can serve as a source of nutrition for humans. In this study, a rapid and effective LC/ MS method coupled with pre-processing methods was developed and validated for the accurate quantification of Ade, AMP, ADP and ATP in royal jelly. To achieve the best extraction efficiency, two pretreatment methods, namely, solid-phase extraction (SPE) and dispersive solid-phase extraction (dSPE), were developed and investigated. Silica-based cyanopropyl (CN) liquid chromatography was employed using pH programming with a quaternary mobile phase system for the analyses. The total LC/MS run time was less than 12 min with a constant flow rate of 0.25 mL/min. The linear range were 2.5–1000 ng/mL with a correlation coefficient r = 0.9995. The limit of detection (LOD) of Ade, AMP, ADP and ATP was 1, 1, 2.5 and 5 ng/mL; the limit of quantitation (LOQ) was 2.5, 2.5, 5 and 10 ng/mL, respectively. Precision (RSD% <10.5%) and accuracy (recovery 81.3–118.4%) were satisfactory for both two pre-processing methods. Nucleotides were successfully quantified from 2-day and 3-day royal jelly samples, with concentrations within 6.2–2126.0 mg/kg.

Bayesian Quantification for Coherent Anti-Stokes Raman Scattering Spectroscopy.

We propose a Bayesian statistical model for analyzing coherent anti-Stokes Raman scattering (CARS) spectra. Our quantitative analysis includes statistical estimation of constituent line-shape parameters, the underlying Raman signal, the error-corrected CARS spectrum, and the measured CARS spectrum. As such, this work enables extensive uncertainty quantification in the context of CARS spectroscopy. Furthermore, we present an unsupervised method for improving spectral resolution of Raman-like spectra requiring little to no a priori information. Finally, the recently proposed wavelet prism method for correcting the experimental artifacts in CARS is enhanced by using interpolation techniques for wavelets. The method is validated using CARS spectra of adenosine mono-, di-, and triphosphate in water, as well as equimolar aqueous solutions of d-fructose, d-glucose, and their disaccharide combination sucrose.

Mutations of the gene FNIP1 associated with a syndromic autosomal recessive immunodeficiency with cardiomyopathy and pre‐excitation syndrome

AMPK (adenosine monophosphate-activated protein kinase) is phosphorylated (AMPK-P) in response to low energy through allosteric activation by Adenosine mono- or diphosphate (AMP/ADP). Folliculin (FLCN) and the FLCN-interacting proteins 1 and 2 (FNIP1, 2) modulate AMPK. FNIP1 deficiency patients have a AMPK-P gain of function phenotype with hypertrophic cardiomyopathy, Wolff-Parkinson-White pre-excitation syndrome, myopathy of skeletal muscles and combined immunodeficiency.

Inhibition of CXCR4 and CXCR7 Is Protective in Acute Peritoneal Inflammation.

Our previous studies revealed a pivotal role of the chemokine stromal cell-derived factor (SDF)-1 and its receptors CXCR4 and CXCR7 on migratory behavior of polymorphonuclear granulocytes (PMNs) in pulmonary inflammation. Thereby, the SDF-1-CXCR4/CXCR7-axis was linked with adenosine signaling. However, the role of the SDF-1 receptors CXCR4 and CXCR7 in acute inflammatory peritonitis and peritonitis-related sepsis still remained unknown. The presented study provides new insight on the mechanism of a selective inhibition of CXCR4 (AMD3100) and CXCR7 (CCX771) in two models of peritonitis and peritonitis-related sepsis by injection of zymosan and fecal solution. We observed an increased expression of SDF-1, CXCR4, and CXCR7 in peritoneal tissue and various organs during acute inflammatory peritonitis. Selective inhibition of CXCR4 and CXCR7 reduced PMN accumulation in the peritoneal fluid and infiltration of neutrophils in lung and liver tissue in both models. Both inhibitors had no anti-inflammatory effects in A2B knockout animals (A2B–/–). AMD3100 and CCX771 treatment reduced capillary leakage and increased formation of tight junctions as a marker for microvascular permeability in wild type animals. In contrast, both inhibitors failed to improve capillary leakage in A2B–/– animals, highlighting the impact of the A2B-receptor in SDF-1 mediated signaling. After inflammation, the CXCR4 and CXCR7 antagonist induced an enhanced expression of the protective A2B adenosine receptor and an increased activation of cAMP (cyclic adenosine mono phosphate) response element-binding protein (CREB), as downstream signaling pathway of A2B. The CXCR4- and CXCR7-inhibitor reduced the release of cytokines in wild type animals via decreased intracellular phosphorylation of ERK and NFκB p65. In vitro, CXCR4 and CXCR7 antagonism diminished the chemokine release of human cells and increased cellular integrity by enhancing the expression of tight junctions. These protective effects were linked with functional A2B-receptor signaling, confirming our in vivo data. In conclusion, our study revealed new protective aspects of the pharmacological modulation of the SDF-1-CXCR4/CXCR7-axis during acute peritoneal inflammation in terms of the two hallmarks PMN migration and barrier integrity. Both anti-inflammatory effects were linked with functional adenosine A2B-receptor signaling.

ACE overexpression in myeloid cells increases oxidative metabolism and cellular ATP

ACE overexpression in myeloid cells increases oxidative metabolism and cellular ATP

A prospective study on effectiveness of drotaverine in acceleration of labor

Background: Labor is a naturally occurring physiological process associated with uterine contractions, effacement, dilatation of cervix and descent of presenting part. Drotaverine hydrochloride is a non-anticholinergic isoquinoline derivative which acts by elevating intracellular cyclic Adenosine Mono Phosphate (cAMP) and cyclic Guanosine Mono Phosphate (cGMP) promoting smooth muscle relaxation.&#x0D; Materials and Method: This was a hospital based prospective study on effectiveness of Drotaverine Hydrochloride on enhancing dilatation of cervix and acceleration of active phase of labor. The sample size was 100. Fifty cases of women in active phase of labor received injection drotaverine hydrochloride 40 mg (group i) and fifty cases of women did not receive any drug (group ii) among those at term with singleton pregnancy and vertex presentation. Variables like maternal age, interval between administration of drug and delivery, mode of delivery, apgar score at 5 minutes, NCU (Neonatal Care Unit) admission and neonatal outcomes were recorded. Data analysis was done with the help of SPSS program.&#x0D; Results: The mean interval between drug administration to delivery in primipara and multipara in group i was 3.05 hours and 2.31 hours while in group ii was 4.5 hours and 3.75 hours respectively. The mean interval between drug administration and delivery was shorter in both groups of multipara. In group i, 96% had normal delivery and 4 % had vacuum delivery and in group ii 90% and 10% had normal delivery and vacuum delivery respectively. None of the participants had caeserian section. There were no perinatal mortalities.&#x0D; Conclusion: The administration of drug Drotaverine Hydrochloride is effective in shortening duration of labor with favorable feto-maternal outcome.

Elevation of hepatic autophagy and antioxidative capacity by endurance exercise is associated with suppression of apoptosis in mice

Introduction and objectivesEndurance exercise (EXE) has emerged as a potent inducer of autophagy essential in maintaining cellular homeostasis in various tissues; however, the functional significance and molecular mechanisms of EXE-induced autophagy in the liver remain unclear. Thus, the aim of this study is to examine the signaling nexus of hepatic autophagy pathways occurring during acute EXE and a potential crosstalk between autophagy and apoptosis. Materials and methodsC57BL/6 male mice were randomly assigned to sedentary control group (CON, n=9) and endurance exercise (EXE, n=9). Mice assigned to EXE were gradually acclimated to treadmill running and ran for 60min per day for five consecutive days. ResultsOur data showed that EXE promoted hepatic autophagy via activation of canonical autophagy signaling pathways via mediating microtubule-associated protein B-light chain 3 II (LC3-II), autophagy protein 7 (ATG7), phosphorylated adenosine mono phosphate-activated protein kinase (p-AMPK), CATHEPSIN L, lysosome-associated membrane protein 2 (LAMP2), and a reduction in p62. Interestingly, this autophagy promotion concurred with enhanced anabolic activation via AKT-mammalian target of rapamycin (mTOR)-p70S6K signaling cascade and enhanced antioxidant capacity such as copper zinc superoxide dismutase (CuZnSOD), glutathione peroxidase (GPX), and peroxiredoxin 3 (PRX3), known to be as antagonists of autophagy. Moreover, exercise-induced autophagy was inversely related to apoptosis in the liver. ConclusionsOur findings indicate that improved autophagy and antioxidant capacity, and potentiated anabolic signaling may be a potent non-pharmacological therapeutic strategy against diverse liver diseases.

Class III Polyphosphate Kinase 2 Enzymes Catalyze the Pyrophosphorylation of Adenosine-5'-Monophosphate.

Polyphosphate kinase 2 (PPK2) transfer phosphate from inorganic polyphosphate to nucleotides. According to their activity, PPK2 enzymes are classified into three groups. Among them, class III enzymes catalyze both the phosphorylation of nucleotide mono- to diphosphates and di- to triphosphates by using polyphosphate, which is a very inexpensive substrate. Therefore, class III enzymes are very attractive for use in biotechnological applications. Despite several studies on class III enzymes, a detailed mechanism of how phosphate is transferred from the polyphosphate to the nucleotide remains to be elucidated. Herein, it is reported that PPK2 class III enzymes from two different bacterial species catalyze the phosphorylation of adenosine mono- (AMP) into triphosphate (ATP) not only through step-by-step phosphorylation, but also by pyrophosphorylation. These are the first PPK2 enzymes that have been shown to possess polyphosphate-dependent pyrophosphorylation activity.

Confinement and Time Immemorial: Prebiotic Synthesis of Nucleotides on a Porous Mineral Nanoreactor.

We report the successful one-pot synthesis of adenosine mono-, di-, and triphosphate in the confined space of a mordenite zeolite. This is also the first report of ATP synthesized onto a porous mineral surface. The results revealed a plausible prebiotic route to ribonucleotides and highlighted the contribution of microporous minerals in the origins of life.