Enhancing ferryl accumulation in HO-dependent cytochrome P450s.

A facile strategy is presented to enhance the accumulation of ferryl (iron(IV)-oxo) species in HO dependent cytochrome P450s (CYPs) of the CYP152 family. We report the characterization of a highly chemoselective CYP decarboxylase from Staphylococcus aureus (OleT) that is soluble at high concentrations. Examination of OleT Compound I (CpdI) accumulation with a variety of fatty acid substrates reveals a dependence on resting spin-state equilibrium.

Excision of a Protein-Derived Amine for -Aminobenzoate Assembly by the Self-Sacrificial Heterobimetallic Protein CADD.

Chlamydia protein associating with death domains (CADD), the founding member of a recently discovered class of nonheme dimetal enzymes termed hemeoxygenase-like dimetaloxidases (HDOs), plays an indispensable role in pathogen survival. CADD orchestrates the biosynthesis of -aminobenzoic acid (ABA) for integration into folate via the self-sacrificial excision of a protein-derived tyrosine (Tyr27) and several additional processing steps, the nature and timing of which have yet to be fully clarified. Nuclear magnetic resonance (NMR) and proteomics approaches reveal the source and probable timing of amine installation by a neighboring lysine (Lys152).

A Ferric-Superoxide Intermediate Initiates P450-Catalyzed Cyclic Dipeptide Dimerization.

The cytochrome P450 (CYP) AspB is involved in the biosynthesis of the diketopiperazine (DKP) aspergilazine A. Tryptophan-linked dimeric DKP alkaloids are a large family of natural products that are found in numerous species and exhibit broad and often potent bioactivity. The proposed mechanisms for C-N bond formation by AspB, and similar C-C bond formations by related CYPs, have invoked the use of a ferryl-intermediate as an oxidant to promote substrate dimerization.

Dimer-assisted mechanism of (un)saturated fatty acid decarboxylation for alkene production.

The enzymatic decarboxylation of fatty acids (FAs) represents an advance toward the development of biological routes to produce drop-in hydrocarbons. The current mechanism for the P450-catalyzed decarboxylation has been largely established from the bacterial cytochrome P450 OleT. Herein, we describe OleTP, a poly-unsaturated alkene-producing decarboxylase that outrivals the functional properties of the model enzyme and exploits a distinct molecular mechanism for substrate binding and chemoselectivity.

Beta-Blockers in Pregnancy: Clinical Update.

Purpose Of Review: The aim of this review was to determine the anticipated benefits and adverse effects of beta-blockers in pregnant women with hypertension. The other issue was to assess the possible adverse effects of beta-blockers for their babies and provide current consensus recommendations for appropriate selection and individualized antihypertensive treatment with beta-blockers in pregnancy-associated hypertension.

Recent Findings: Hypertensive disorders of pregnancy are a major cause of maternal and fetal morbidity, with consequences later in life.

Self-sacrificial tyrosine cleavage by an Fe:Mn oxygenase for the biosynthesis of -aminobenzoate in .

Chlamydia protein associating with death domains (CADD) is involved in the biosynthesis of -aminobenzoate (pABA), an essential component of the folate cofactor that is required for the survival and proliferation of the human pathogen . The pathway used by for pABA synthesis differs from the canonical multi-enzyme pathway used by most bacteria that relies on chorismate as a metabolic precursor. Rather, recent work showed pABA formation by CADD derives from l-tyrosine.

Third-wave psychotherapies to promote mental health in epilepsy: An updated systematic review.

Purpose/objective: Research on third-wave cognitive behavioral therapies has burgeoned over the last ten years. However, questions remain about the effectiveness of these therapies for people with epilepsy. This article provides an up-to-date review of the current evidence-base.

Experimental and Theoretical Examination of the Kinetic Isotope Effect in Cytochrome P450 Decarboxylase OleT.

Using a combination of experimental studies, theory, simulation, and modeling, we investigate the hydrogen atom transfer (HAT) reaction by the high-valent ferryl cytochrome P450 (CYP) intermediate known as Compound I, a species that is central to innumerable and important detoxification and biosynthetic reactions. The P450 decarboxylase known as OleT converts fatty acids, a sustainable biological feedstock, into terminal alkenes and thus is of high interest as a potential means to produce fungible biofuels. Previous experimental work has established the intermediacy of Compound I in the C─C scission reaction catalyzed by OleT and an unprecedented ability to monitor the HAT process in the presence of bound fatty acid substrates.

Modeling the Ligand Effect on the Structure of CYP 450 Within the Density Functional Theory.

An improved understanding of the P450 structure is relevant to the development of biomimetic catalysts and inhibitors for controlled CH-bond activation, an outstanding challenge of synthetic chemistry. Motivated by the experimental findings of an unusually short Fe-S bond of 2.18 Å for the wild-type (WT) OleT P450 decarboxylase relative to a cysteine pocket mutant form (A369P), a computational model that captures the effect of the thiolate axial ligand on the iron-sulfur distance is presented.

Stimuli-Modulated Metal Oxidation States in Photochromic MOFs.

Tuning metal oxidation states in metal-organic framework (MOF) nodes by switching between two discrete linker photoisomers via an external stimulus was probed for the first time. On the examples of three novel photochromic copper-based frameworks, we demonstrated the capability of switching between +2 and +1 oxidation states, on demand. In addition to crystallographic methods used for material characterization, the role of the photochromic moieties for tuning the oxidation state was probed via conductivity measurements, cyclic voltammetry, and electron paramagnetic resonance, X-ray photoelectron, and diffuse reflectance spectroscopies.

Structural and functional characterization of β-cyanoalanine synthase from Tetranychus urticae.

Tetranychus urticae is a polyphagous spider mite that can feed on more than 1100 plant species including cyanogenic plants. The herbivore genome contains a horizontally acquired gene tetur10g01570 (TuCAS) that was previously shown to participate in cyanide detoxification. To understand the structure and determine the function of TuCAS in T.

BesC Initiates C-C Cleavage through a Substrate-Triggered and Reactive Diferric-Peroxo Intermediate.

BesC catalyzes the iron- and O-dependent cleavage of 4-chloro-l-lysine to form 4-chloro-l-allylglycine, formaldehyde, and ammonia. This process is a critical step for a biosynthetic pathway that generates a terminal alkyne amino acid which can be leveraged as a useful bio-orthogonal handle for protein labeling. As a member of an emerging family of diiron enzymes that are typified by their heme oxygenase-like fold and a very similar set of coordinating ligands, recently termed HDOs, BesC performs an unusual type of carbon-carbon cleavage reaction that is a significant departure from reactions catalyzed by canonical dinuclear-iron enzymes.

Joint ESH excellence centers' national meeting on renal sympathetic denervation: A Greek experts' survey.

Objective: The efficacy of renal sympathetic denervation (RDN) has been affirmed by a number of recent clinical studies, despite controversies in this field over the last five years. Therefore, it is of paramount importance that hypertension experts debate the merits of RDN by revealing and expressing their personal beliefs and perspectives regarding this procedure.

Methods: A cross-sectional survey was conducted among Greek leaders of the Hypertension Excellence Centers with the use of a closed-type questionnaire specifically designed to elicit information and evaluate the respondent's views and perspectives about RDN efficacy, safety and ideal target patient population.

A single-center, prospective, observational study on maternal smoking during pregnancy in Greece: The HELENA study.

Introduction: The unequivocal association between exposure to smoke and numerous complications of pregnancy, demonstrated in the last decades, has led to a significant decrease of smoking rates in pregnancy. The aim of the present study was to determine the prevalence of maternal smoking and to elucidate factors predisposing to it among pregnant women in Athens, Greece.

Methods: A population of 1700 pregnant women (mean age: 31.

Beta Blockers and Chronic Obstructive Pulmonary Disease (COPD): Sum of Evidence.

Approximately half a century has passed since the discovery of beta-blockers. Then, their prime therapeutic purpose was to treat angina and cardiac arrhythmias; nowadays, beta-blockers' usage and effectiveness are extended to treat other cardiovascular diseases, such as hypertension, congestive heart failure, and coronary artery disease. Safety concerns were raised about beta- blockers and their use for chronic obstructive pulmonary disease (COPD) patients with concurrent cardiovascular disease.

Direct Identification of Mixed-Metal Centers in Metal-Organic Frameworks: Cu(BTC) Transmetalated with Rh Ions.

Raman spectroscopy was used to establish direct evidence of heterometallic metal centers in a metal-organic framework (MOF). The Cu(BTC) MOF HKUST-1 (BTC = benzenetricarboxylate) was transmetalated by heating it in a solution of RhCl to substitute Rh ions for Cu ions in the dinuclear paddlewheel nodes of the framework. In addition to the Cu-Cu and Rh-Rh stretching modes, Raman spectra of (CuRh)(BTC) show the Cu-Rh stretching mode, indicating that mixed-metal Cu-Rh nodes are formed after transmetalation.

Postpartum Hypertension.

Purpose Of Review: Hypertension affects approximately 10% of pregnancies and may persist in the postpartum period. Furthermore, de novo hypertension may present after delivery, but its exact prevalence is not verified. Both types of hypertension expose the mother to eventually severe complications like eclampsia, stroke, pulmonary edema, and HELLP (hemolysis, elevated liver enzymes, low platelet) syndrome.

Antidiabetic drugs and blood pressure changes.

New era antidiabetic drugs are characterized by cardiovascular safety, including specific outcome benefits observed in randomized clinical trials (RCTs). It has been postulated that the favorable effects of new antidiabetic agents are related both to better control of blood pressure (BP) levels and to activation of multiple anti-atherosclerotic properties. In this review, we aimed to assess whether antidiabetic drugs have a pressor effect in glucose control and outcome-oriented RCTs, and to summarize the activated pathophysiological mechanisms relevant to BP control following the use of different antidiabetic drug classes.

Enhanced P450 fatty acid decarboxylase catalysis by glucose oxidase coupling and co-assembly for biofuel generation.

Cytochrome P450 OleT is a fatty acid decarboxylase that uses hydrogen peroxide (HO) to catalyze the production of terminal alkenes, which are industrially important chemicals with biofuel and synthetic applications. Despite its requirement for large turnover levels, high concentrations of HO may cause heme group degradation, diminishing enzymatic activity and limiting broad application for synthesis. Here, we report an artificial enzyme cascade composed of glucose oxidase (GOx) and OleT from Staphylococcus aureus for efficient terminal alkene production.

Microfluidic-assisted polymer-protein assembly to fabricate homogeneous functionalnanoparticles.

Functional polymer-protein nanoparticles (NPs) have broad applications in biotechnology and nanotechnology. In principle, controllable and vigorous mixing is required to fabricate homogeneous NPs, which remains a challenge via conventional bulk synthetic methods. In this study, an electrokinetics (EK) based microfluidic reactor with fast mixing is explored to assemble functional proteins with polymers in an ethanol/water co-solvent system.

The Diiron Monooxygenase CmlA from Chloramphenicol Biosynthesis Allows Reconstitution of β-Hydroxylation during Glycopeptide Antibiotic Biosynthesis.

β-Hydroxylation plays an important role in the nonribosomal peptide biosynthesis of many important natural products, including bleomycin, chloramphenicol, and the glycopeptide antibiotics (GPAs). Various oxidative enzymes have been implicated in such a process, with the mechanism of incorporation varying from installation of hydroxyl groups in amino acid precursors prior to adenylation to direct amino acid oxidation during peptide assembly. In this work, we demonstrate the utility and scope of the unusual nonheme diiron monooxygenase CmlA from chloramphenicol biosynthesis for the β-hydroxylation of a diverse range of carrier protein bound substrates by adapting this enzyme as a non-native -acting enzyme within NRPS-mediated GPA biosynthesis.

Plasmin-Cleavable Nanoparticles for On-Demand Release of Morphogens in Vascularized Osteogenesis.

The objective of this work was to engineer self-assembled nanoparticles (NPs) for on-demand release of bone morphogenetic protein-2 (BMP2) and vascular endothelial growth factor (VEGF) in response to enzymes secreted by the migrating human mesenchymal stem cells (hMSCs) and human endothelial colony forming cells (ECFCs) to induce osteogenesis and vasculogenesis. Gene expression profiling experiments revealed that hMSCs and ECFCs, encapsulated in osteogenic/vasculogenic hydrogels, expressed considerable levels of plasminogen, urokinase plasminogen activator and its receptor uPAR, and tissue plasminogen activator. Therefore, the plasmin-cleavable lysine-phenylalanine-lysine-threonine (KFKT) was used to generate enzymatically cleavable NPs.