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In the absence of naturally available galactofuranose-specific lectin, we report herein the bioengineering of GalfNeoLect, from the first cloned wild-type galactofuranosidase (Streptomyces sp. strain JHA19), which recognises and binds a single monosaccharide that is only related to nonmammalian species, usually pathogenic microorganisms. We kinetically characterised the GalfNeoLect to confirm attenuation of hydrolytic activity and used competitive inhibition assay, with close structural analogues of Galf, to show that it conserved interaction with its original substrate. We synthetised the bovine serum albumin-based neoglycoprotein (GalfNGP), carrying the multivalent Galf units, as a suitable ligand and high-avidity system for the recognition of GalfNeoLect which we successfully tested directly with the galactomannan spores of Aspergillus brasiliensis (ATCC 16404). Altogether, our results indicate that GalfNeoLect has the necessary versatility and plasticity to be used in both research and diagnostic lectin-based applications. [ABSTRACT FROM AUTHOR]

A first access to mono‐, di‐ and tri‐(Het)arylated pyrazolo[5,1‐b]oxazoles is reported. The series were generated from a library of 3‐(Het)arylpyrazolo[5,1‐b]oxazole platforms selectively functionalized through regioselective arylation procedures. The regioselective functionalization in C‐2 and C‐7 positions was investigated. Each Palladium‐catalyzed cross‐coupling condition was optimized and a representative library of the scope and limitations of the reactions was studied. [ABSTRACT FROM AUTHOR]

Inhibition of kynurenine 3-monooxygenase (KMO), an enzyme in the eukaryotic tryptophan catabolic pathway (that is, kynurenine pathway), leads to amelioration of Huntington's-disease-relevant phenotypes in yeast, fruitfly and mouse models (1-5), [...]

Whereas the mechanism and functional aspects of PAR synthesis have been extensively characterized, the present understanding of the PAR-degradation pathways catalysed by PARG is comparatively poor. Until now, the catalytic [...], Post-translational modification of proteins by poly(ADP-ribosyl) ation regulates many cellular pathways that are critical for genome stability, including DNA repair, chromatin structure, mitosis and apoptosis (1). Poly(ADP-ribose) (PAR) is composed of repeating ADP-ribose units linked via a unique glycosidic ribose-ribose bond, and is synthesized from NAD by PAR polymerases (1,2). PAR glycohydrolase (PARG) is the only protein capable of specific hydrolysis of the ribose-ribose bonds present in PAR chains; its deficiency leads to cell death (3,4). Here we show that filamentous fungi and a number of bacteria possess a divergent form of PARG that has all the main characteristics of the human PARG enzyme. We present the first PARG crystal structure (derived from the bacterium Thermomonospora curvata), which reveals that the PARG catalytic domain is a distant member of the ubiquitous ADP-ribose-binding macrodomain family (5,6). High-resolution structures of T. curvata PARG in complexes with ADP-ribose and the PARG inhibitor ADP-HPD, complemented by biochemical studies, allow us to propose a model for PAR binding and catalysis by PARG. The insights into the PARG structure and catalytic mechanism should greatly improve our understanding of how PARG activity controls reversible protein poly(ADP-ribosyl) ation and potentially of how the defects in this regulation are linked to human disease.

Author(s): Mary Ortmayer [1]; Pierre Lafite [1]; Binuraj R. K. Menon [1]; Tewes Tralau [1]; Karl Fisher [1]; Lukas Denkhaus [1]; Nigel S. Scrutton [1]; Stephen E. J. Rigby [1]; [...]

The oxidation of six derivatives of terfenadone by recombinant human CYP2J2 (CYP = cytochrome P450) is examined. Results reveal that CYP2J2 showed an unusual regioselectivity in favor of the hydroxylation of the substrate terminal chain at the weakly reactive homobenzylic position.