The Rieske Oxygenase SnoT Catalyzes 2′′-Hydroxylation of l-Rhodosamine in Nogalamycin Biosynthesis

Nogalamycin is an anthracycline anti-cancer agent that intercalates into the DNA double helix. The binding is facilitated by two carbohydrate units, l -nogalose and l -nogalamine, that interact with the minor and major grooves of DNA, respectively. However, recent investigations have shown that nogalamycin biosynthesis proceeds through the attachment of l -rhodosamine (2′′-deoxy-4′′-epi-l -nogalamine) to the aglycone. Herein, we demonstrate that the Rieske enzyme SnoT catalyzes 2′′-hydroxylation of l -rhodosamine as an initial post-glycosylation step. Furthermore, we establish that the reaction order continues with 2–5′′ carbocyclization and 4′′ epimerization by the non-heme iron and 2-oxoglutarate-dependent enzymes SnoK and SnoN, respectively. These late-stage tailoring steps are important for the bioactivity of nogalamycin due to involvement of the 2′′- and 4′′-hydroxy groups of l -nogalamine in hydrogen bonding interactions with DNA.     

Comparison of a new amylase found in barley with the amylases of the fungi of barley husk

The electrophoretic and antigenic properties of a new, partly characterised barley amylase have been compared with those of the different amylases produced by fungi living on barley husk. The purpose of this work was to ascertain whether the new amylase originates from barley or from the fungal contaminant. It was found that none of the fungi enriched from the grains in question produced amylases which had the same electrophoretic mobility as the new barley amylase or reacted with the antiserum made against it. On the basis of these results it seems clear that the new amylase originates from barley.     

Catherine Bauer and six riddles of modernism

In her most striking contributions to the debates on public housing in America, Catherine Bauer posed riddles. Yet if her place in the canonic history of the Modern Movement in Britain and America remains enigmatic it is because Bauer's conceptualisations of the riddle of identity and desire - so crucial to her writing and initiatives - are recorded only in her intimate correspondence with cultural critic Lewis Mumford, which are as yet unpublished. This essay draws attention to Bauer's use of riddles to pose difficult questions about the absence of social housing in America, a riddle about public-private provision and appropriate action and housing's place in the history of architecture. The paper argues that Catherine Bauer belongs to the modernist canon for her breadth of engagement: for pursuing the moral, philosophical, formal, economic and political implications of modern housing in America.     

Catherine Bauer and six riddles of modernism

In her most striking contributions to the debates on public housing in America, Catherine Bauer posed riddles. Yet if her place in the canonic history of the Modern Movement in Britain and America remains enigmatic it is because Bauer's conceptualisations of the riddle of identity and desire - so crucial to her writing and initiatives - are recorded only in her intimate correspondence with cultural critic Lewis Mumford, which are as yet unpublished. This essay draws attention to Bauer's use of riddles to pose difficult questions about the absence of social housing in America, a riddle about public-private provision and appropriate action and housing's place in the history of architecture. The paper argues that Catherine Bauer belongs to the modernist canon for her breadth of engagement: for pursuing the moral, philosophical, formal, economic and political implications of modern housing in America.     

Modelling of organic liquid-phase decomposition reactions through gas-phase product analysis: Model systems and peracetic acid

A new method for modelling of liquid-phase decomposition reactions was developed. The method is based on rapid on-line mass spectrometric analysis of liberated products in gas phase. The experimental set-up and the generalized modelling principles were introduced. The approach was demonstrated with first and zero order as well as for complex decomposition kinetics (decomposition of peracetic acid). The interaction of decomposition kinetics and mass-transfer effects was illustrated with theoretical and real reaction conditions. The approach is generally applicable to any liquid-phase decomposition, provided that gaseous products can be quantitatively analyzed.     

On-line measurements in pig carcass classification: Repeatability and variation caused by the operator and the copy of instrument

For nearly all pigs slaughtered in the EU, the lean meat content is assessed on-line at the slaughter line. The assessment is made indirectly by an instrument performing a number of informative measurements including the thickness of back fat as one of the most important and common measurements. Several types of instruments are used for making the measurements. The quality of the calibration (the prediction ability) has to be approved by the EU Commission. However, the maintenance of instruments, training of operators, working conditions and other factors influencing the routine are quite as important for the accuracy as the calibration. As a part of an EU funded project, partners representing thirteen European countries have investigated the instruments used in their countries focusing on the precision of indirect measurements. The preconditions have differed considerably between the countries resulting in a wide range of estimates of the repeatability and the reproducibility (precision) of fat and muscle thickness. Totally, there have been three different types of manual instruments - invasive probe instruments from three manufacturers, non-invasive ultrasound and callipers. Furthermore, the precision of two automatic instruments with respect to lean meat content has partly been estimated. Even though neither the aim nor the design of the experiments was set for a direct comparison between different instruments, none of them seemed to deviate notably from the others with respect to the precision of fat thickness. In this study, the only investigated influencing factors were the variations in operators and copies of instruments. Generally, the variations between operators were more important than the variation between copies of the same type of instrument.     

Prevalence of Listeria monocytogenes in broilers at the abattoir, processing plant, and retail level.

The environment and products from two broiler abattoirs and processing plants and raw broiler pieces at the retail level were sampled for Listeria monocytogenes in order to evaluate the contamination level of the broiler carcasses and products. Sampling started in the slaughtering process and finished with raw broiler meat or ready-to-eat cooked product. Sampling sites positive for L. monocytogenes at the broiler abattoir were the air chiller, the skin-removing machine, and the conveyor belt leading to the packaging area. The L monocytogenes contamination rate varied from 1 to 19% between the two plants studied. Furthermore, 62% (38 of 61) of the raw broiler pieces, bought from retail stores, were positive for L. monocytogenes. Altogether, 136 L. monocytogenes isolates were obtained for serotyping and pulsed-field gel electrophoresis (PFGE) characterization performed with two rare-cutting enzymes (ApaI and AscI). Altogether three serotypes (1/2a, 1/2c, and 4b) and 14 different PFGE types were obtained using information provided from both ApaI and AscI patterns for discrimination basis. The two broiler abattoirs studied did not share the same PFGE types. However, the same PFGE types found in the raw broiler pieces at the retail level were also found in the broiler abattoirs where the broilers had been slaughtered.     

Enzyme activities,dietary fibre components and rheological properties of wholemeal flours from rye cultivars grown in Finland

Total and soluble dietary fibre, total and soluble pentosan and β‐glucan contents, activities of α‐amylase (EC 3.2.1.1) and endo‐β‐xylanase (EC 3.2.1.8) and viscous properties of aqueous suspensions of wholemeal flours during heating were determined in nine winter rye cultivars (Secale cereale L) grown in Finland in 1998–2001. There was marked annual and varietal differences in grain quality. In the rainy summer 1998 the yield was low, grains were small and dietary fibre content of the grains was high. Xylanase activity of the grains was high, which corresponded to the high content of soluble pentosans. In the dry summer of 1999, the pentosan content of the grains was low and β‐glucan content high. The effect of weather conditions and cultivar were also apparent in the differences in falling numbers, amylogram and swelling curve results. The two hybrid rye cultivars Esprit and Picasso had consistently highest falling numbers and amylogram peak viscosities. The activities of α‐amylase and xylanase had a moderate positive correlation with total pentosan content and the content of soluble pentosan. Xylanase activity had better correlation with the viscous properties of flour–water suspensions than α‐amylase. Surprisingly, α‐amylase activity had only a moderate negative correlation with falling number. Copyright © 2005 Society of Chemical Industry     

Effect of CLA on the cellular lipids of <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis>

The yeast Saccharomyces cerevisiae was cultivated in the presence of free CLA that was either a pure trans-10, cis-12 isomer, a pure cis-9, trans-11 isomer, or a 1∶1 mixture of the two, and the influence of these supplementations on the content and FA composition of the lipids in the yeast was determined. Neither the pure isomers nor their 1∶1 mixture influenced the growth of the yeast, but the trans-10, cis-12 isomer reduced the amount of cellular lipids by 40%. The reduction in total cellular lipids by the trans-10, cis-12 CLA was due to a reduction in TAG. Both of the isomers were incorporated into the yeast lipids, reaching a proportion of about 33% in TAG. With the incorporation of CLA, the yeast reduced the amount and desaturation of endogenously synthesized FA. These clear and pronounced isomer-specific effects of CLA on the yeast suggest that yeast might be a useful model to obtain a more comprehensive view of the mechanisms of the action of CLA on lipid metabolism.