Discovery and characterization of NADH oxidases for selective sustainable synthesis of 5-hydroxymethylfuran carboxylic acid.

Efficient regeneration of NAD remains a significant challenge for oxidative biotransformations. In order to identify enzymes with higher activity and stability, a panel of NADH oxidases (Nox) was investigated in the regeneration of nicotinamide cofactors for the oxidation of hydroxymethyl furfural (HMF) to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA). We present novel Nox that exhibit remarkable catalytic activities, elevated thermal and pH stabilities, and higher intrinsic flavin loadings, thus eliminating the need for external flavin addition.

Structure of human phospholipase D3, a single-strand exonuclease associated with Alzheimer's disease.

Phospholipase D3 (PLD3) has emerged as an important 5'-exonuclease in charge of removing single-stranded DNA in lysosomes. Rare genetic variants of the gene encoding PLD3 have been implicated in late-onset Alzheimer's disease (AD). Ishii et al.

Analysis of homodimer formation in 12-oxophytodienoate reductase 3 in solutio and crystallo challenges the physiological role of the dimer.

12-oxophytodienoate reductase 3 (OPR3) is a key enzyme in the biosynthesis of jasmonoyl-L-isoleucine, the receptor-active form of jasmonic acid and crucial signaling molecule in plant defense. OPR3 was initially crystallized as a self-inhibitory dimer, implying that homodimerization regulates enzymatic activity in response to biotic and abiotic stresses. Since a sulfate ion is bound to Y364, mimicking a phosphorylated tyrosine, it was suggested that dimer formation might be controlled by reversible phosphorylation of Y364 in vivo.

Asymmetric Synthesis of Chiral 2-Cyclohexenones with Quaternary Stereocenters via Ene-Reductase Catalyzed Desymmetrization of 2,5-Cyclohexadienones.

Stereoselective synthesis of quaternary stereocenters represents a significant challenge in organic chemistry. Herein, we describe the use of ene-reductases OPR3 and YqjM for the efficient asymmetric synthesis of chiral 4,4-disubstituted 2-cyclohexenones via desymmetrizing hydrogenation of prochiral 4,4-disubstituted 2,5-cyclohexadienones. This transformation breaks the symmetry of the cyclohexadienone substrates, generating valuable quaternary stereocenters with high enantioselectivities (ee, up to >99%).

Fus-SMO: Kinetics, Biochemical Characterisation and In Silico Modelling of a Chimeric Styrene Monooxygenase Demonstrating Quantitative Coupling Efficiency.

The styrene monooxygenase, a two-component enzymatic system for styrene epoxidation, was characterised through the study of Fus-SMO - a chimera resulting from the fusion of StyA and StyB using a flexible linker. Notably, it remains debated whether the transfer of FADH from StyB to StyA occurs through diffusion, channeling, or a combination of both. Fus-SMO was identified as a trimer with one bound FAD molecule.

Loop 6 and the β-hairpin flap are structural hotspots that determine cofactor specificity in the FMN-dependent family of ene-reductases.

Flavin mononucleotide (FMN)-dependent ene-reductases constitute a large family of oxidoreductases that catalyze the enantiospecific reduction of carbon-carbon double bonds. The reducing equivalents required for substrate reduction are obtained from reduced nicotinamide by hydride transfer. Most ene-reductases significantly prefer, or exclusively accept, either NADPH or NADH.

Simple, fast and inexpensive quantification of glycolate in the urine of patients with primary hyperoxaluria type 1.

In primary hyperoxaluria type 1 excessive endogenous production of oxalate and glycolate leads to increased urinary excretion of these metabolites. Although genetic testing is the most definitive and preferred diagnostic method, quantification of these metabolites is important for the diagnosis and evaluation of potential therapeutic interventions. Current metabolite quantification methods use laborious, technically highly complex and expensive liquid, gas or ion chromatography tandem mass spectrometry, which are available only in selected laboratories worldwide.

In conversation with Peter Macheroux.

Peter Macheroux is Professor of Biochemistry and Head of the Institute of Biochemistry at Graz University of Technology in Austria. Peter's research spans a diverse selection of topics, and his work has contributed significantly towards advancing our understanding of bacterial enzymology, plant physiology and the molecular pathways that underlie human pathophysiology. Among Peter's many scientific achievements, he has led the team that recognised DPP3 as a biomarker for cardiovascular diseases, with the subsequent therapeutic implications of the development of DPP3 inhibitors.

Regioselective Biocatalytic C4-Prenylation of Unprotected Tryptophan Derivatives.

Regioselective carbon-carbon bond formation belongs to the challenging tasks in organic synthesis. In this context, C-C bond formation catalyzed by 4-dimethylallyltryptophan synthases (4-DMATSs) represents a possible tool to regioselectively synthesize C4-prenylated indole derivatives without site-specific preactivation and circumventing the need of protection groups as used in chemical synthetic approaches. In this study, a toolbox of 4-DMATSs to produce a set of 4-dimethylallyl tryptophan and indole derivatives was identified.

Design and synthesis of efficient fluororethylene-peptidomimetic inhibitors of dipeptidyl peptidase III (DPP3).

Dipeptidyl peptidase III (DPP3) is a ubiquitously expressed zinc-dependent peptide cutting enzyme and selectively hydrolyses amide bonds to cleave N-terminal dipeptide fragments off of physiologically important oligopeptides. DPP3 has been found in a multitude of different types of cells and appears to be involved in various physiological processes (e.g.

More important than ever: understanding how plants cope with stress.

In view of the unprecedented rate of current climate change, plants are exposed to an avalanche of adverse environmental conditions that will challenge their ability to cope with abiotic and biotic stresses. These changes are bound to affect crop plants as well, and thus, have the potential to jeopardize food security on a global scale. Hence, it will be critical to understand the molecular defence and adaptation mechanisms that enable plants to thrive in an increasingly hostile environment.

The emerging role of dipeptidyl peptidase 3 in pathophysiology.

Dipeptidyl peptidase 3 (DPP3), a zinc-dependent aminopeptidase, is a highly conserved enzyme among higher animals. The enzyme cleaves dipeptides from the N-terminus of tetra- to decapeptides, thereby taking part in activation as well as degradation of signalling peptides critical in physiological and pathological processes such as blood pressure regulation, nociception, inflammation and cancer. Besides its catalytic activity, DPP3 moonlights as a regulator of the cellular oxidative stress response pathway, e.

Economic purification of recombinant uricase by artificial oil bodies.

Rasburicase is an expensive treatment used to control hyperuricemia caused by tumour lysis syndrome (TLS). In this study, a non-chromatographic method was designed based on nano-oil bodies for convenient and economical purification of the recombinant uricase. For this purpose, two chimaeras were synthesized with a different arrangement of the uricase, caleosin and intein fragments.

Efficient Entropy-Driven Inhibition of Dipeptidyl Peptidase III by Hydroxyethylene Transition-State Peptidomimetics.

Dipeptidyl peptidase III (DPP3) is a ubiquitously expressed Zn-dependent protease, which plays an important role in regulating endogenous peptide hormones, such as enkephalins or angiotensins. In previous biophysical studies, it could be shown that substrate binding is driven by a large entropic contribution due to the release of water molecules from the closing binding cleft. Here, the design, synthesis and biophysical characterization of peptidomimetic inhibitors is reported, using for the first time an hydroxyethylene transition-state mimetic for a metalloprotease.

The scope of flavin-dependent reactions and processes in the model plant Arabidopsis thaliana.

Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are utilized as coenzymes in many biochemical reduction-oxidation reactions owing to the ability of the tricyclic isoalloxazine ring system to employ the oxidized, radical and reduced state. We have analyzed the genome of Arabidopsis thaliana to establish an inventory of genes encoding flavin-dependent enzymes (flavoenzymes) as a basis to explore the range of flavin-dependent biochemical reactions that occur in this model plant. Expectedly, flavoenzymes catalyze many pivotal reactions in primary catabolism, which are connected to the degradation of basic metabolites, such as fatty and amino acids as well as carbohydrates and purines.

The family of sarcosine oxidases: Same reaction, different products.

The subfamily of sarcosine oxidase is a set of enzymes within the larger family of amine oxidases. It is ubiquitously distributed among different kingdoms of life. The member enzymes catalyze the oxidization of an N-methyl amine bond of amino acids to yield unstable imine species that undergo subsequent spontaneous non-enzymatic reactions, forming an array of different products.

The catalytic machinery of the FAD-dependent AtBBE-like protein 15 for alcohol oxidation: Y193 and Y479 form a catalytic base, Q438 and R292 an alkoxide binding site.

Monolignol oxidoreductases are members of the berberine bridge enzyme-like (BBE-like) protein family (pfam 08031) that oxidize monolignols to the corresponding aldehydes. They are FAD-dependent enzymes that exhibit the para-cresolmethylhydroxylase-topology, also known as vanillyl oxidase-topology. Recently, we have reported the structural and biochemical characterization of two monolignol oxidoreductases from Arabidopsis thaliana, AtBBE13 and AtBBE15.

Binding of dipeptidyl peptidase III to the oxidative stress cell sensor Kelch-like ECH-associated protein 1 is a two-step process.

This work is about synergy of theory and experiment in revealing mechanism of binding of dipeptidyl peptidase III (DPP III) and Kelch-like ECH-associated protein 1 (KEAP1), the main cellular sensor of oxidative stress. The NRF2 ̶ KEAP1 signaling pathway is important for cell protection, but it is also impaired in many cancer cells where NRF2 target gene expression leads to resistance to chemotherapeutic drugs. DPP III competitively binds to KEAP1 in the conditions of oxidative stress and induces release of NRF2 and its translocation into nucleus.

The possible role of a bacterial aspartate β-decarboxylase in the biosynthesis of alamandine.

The understanding of the renin-angiotensin system (RAS) has significantly expanded over the last two decades. The elucidation of angiotensin-converting enzyme 2 (ACE2) that converts angiotensin (Ang) II into Ang (1-7) led to the discovery of the cardio-protective axis of the RAS. In addition, novel components of the system, Angiotensin A (Ang A) and alamandine have been identified.

Dipeptidyl peptidase 3 modulates the renin-angiotensin system in mice.

Dipeptidyl peptidase 3 (DPP3) is a zinc-dependent hydrolase involved in degrading oligopeptides with 4-12 amino acid residues. It has been associated with several pathophysiological processes, including blood pressure regulation, pain signaling, and cancer cell defense against oxidative stress. However, the physiological substrates and the cellular pathways that are potentially targeted by DPP3 to mediate these effects remain unknown.