N-linked glycosylation of folded proteins by the bacterial oligosaccharyltransferase

N-linked protein glycosylation is found in all domains of life. In eukaryotes, it is the most abundant protein modification of secretory and membrane proteins, and the process is coupled to protein translocation and folding. We found that in bacteria, N-glycosylation can occur independently of the protein translocation machinery. In an in vitro assay, bacterial oligosaccharyltransferase glycosylated a folded endogenous substrate protein with high efficiency and folded bovine ribonuclease A with low efficiency. Unfolding the eukaryotic substrate greatly increased glycosylation. We propose that in the bacterial system, glycosylation sites are located in flexible parts of folded proteins, whereas the eukaryotic cotranslational glycosylation evolved to a mechanism presenting the substrate in a flexible form before folding.     

Phenolic Compounds Determined by LC-MS/MS and <Emphasis Type="Italic">In Vitro</Emphasis> Antioxidant Capacity of Brazilian Fruits in Two Edible Ripening Stages

The aim of this study was to investigate the free individual phenolics and the in vitro antioxidant capacity of blackberry, acerola, yellow guava, guabiju, jambolan and jabuticaba fruits in two edible stages. Of the thirty-three phenolics investigated by liquid chromatography - tandem mass spectrometry (LC-MS/MS), twenty-five were quantified and the major ones were catechin, isoquercitrin, epicatechin and gallic acid. The highest values for the total phenolic content (in dry matter) were observed for acerola (83.6 to 97.7 mg gallic acid equivalents g^?1 DM) and blackberry (18.9 to 28.3 mg gallic acid equivalents g^?1 DM); however, acerola, jabuticaba, and blackberry showed the highest antioxidant capacities (134.6 to 1120.4 mg Trolox equivalents g^?1 for 2,2-diphenyl-1-picrylhydrazyl and 43.6 to 501.8 μmol Trolox equivalents g^?1 for ferric reducing antioxidant power). For most fruits, the antioxidant capacity decreased during the ripening, possibly due to a decrease in the concentration of most of the phenolics.     

Development options of natural habitats in a post‐mining landscape

Rehabilitation of the post‐mining landscape of Lower Lusatia (Brandenburg, Germany) represents a complex problem: 85 per cent of this area is currently being recultivated for forests or agriculture and 15 per cent is reserved for nature development. After mining, soil conditions are dry, acidic and nutrient poor. The ‘LENAB’ project aimed at conservation strategies and management options for natural habitats. Two competing basic motives of nature conservation on a small or medium scale were defined: (1) close‐to‐naturalness (allowing natural dynamics to take place without human interference) and (2) biodiversity (selective species and habitat protection). An overall strategy for sustainability of a cultural landscape can only be applied to the entire post‐mining landscape. The application of the two basic motives leads to different management options; this is illustrated by two important vegetation types. Copyright © 2000 John Wiley & Sons, Ltd.     

Correction to: Maintenance requirement and utilisation efficiency of energy and protein for ongrowing pikeperch (Sander lucioperca (L.))

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