The contribution of surface residues to membrane binding and ligand transfer by the -tocopherol transfer protein ( -TTP)

Previous work has shown that the -tocopherol transfer protein ( -TTP) can bind to vesicular or immobilized phospholipid membranes. Revealing the molecular mechanisms by which -TTP associates with membranes is thought to be critical to understanding its function and role in the secretion of tocopherol from hepatocytes into the circulation. Calculations presented in the Orientations of Proteins in Membranes database have provided a testable model for the spatial arrangement of -TTP and other CRAL-TRIO family proteins with respect to the lipid bilayer. These calculations predicted that a hydrophobic surface mediates the interaction of -TTP with lipid membranes. To test the validity of these predictions, we used site-directed mutagenesis and examined the substituted mutants with regard to intermembrane ligand transfer, association with lipid layers and biological activity in cultured hepatocytes. Substitution of residues in helices A8 (F165A and F169A) and A10 (I202A, V206A and M209A) decreased the rate of intermembrane ligand transfer as well as protein adsorption to phospholipid bilayers. The largest impairment was observed upon mutation of residues that are predicted to be fully immersed in the lipid bilayer in both apo (open) and holo (closed) conformations such as Phe165 and Phe169. Mutation F169A, and especially F169D, significantly impaired -TTP-assisted secretion of -tocopherol outside cultured hepatocytes. Mutation of selected basic residues (R192H, K211A, and K217A) had little effect on transfer rates, indicating no significant involvement of nonspecific electrostatic interactions with membranes.

Pollen percentage thresholds of Abies alba based on 13-year annual records of pollen deposition in modified Tauber traps: perspectives of application to fossil situations

Abies alba (fir), a submontane tree from Central European mountains and uplands, is of special interest for palaeoecological and palaeoclimate interpretations due to its sensitivity to air and soil humidity. Its present distribution limit in the uplands of SE Poland is still a matter of debate. In the Holocene fir expanded to Poland very late, but early fir populations are supposed to occur in the Šumava Mts (Czech Republic). The study aims: to estimate pollen thresholds for fir presence/absence in Bohemia (Czech Republic) and Poland on the basis of modified Tauber pollen traps; to use these thresholds for tracing fir presence in two pollen diagrams from Poland (Słone and Bezedna lakes) in the border zone between the Roztocze region (with fir forest stands today) and Polesie (where fir has never played an important role); and to investigate how the percentage presence/absence threshold can be used to trace the occurrence and abundance of fir trees in the Šumava Mts based on the pollen diagrams of Rokytecká slat' and Mrtvý luh. The fir pollen thresholds estimated in terms of PAR (pollen accumulation rates or pollen influx) range from 843 (grains cm− 2 year− 1) (Roztocze) to 61 (Krkonoše) and 49 (Šumava). Percentage thresholds range from 0.3% in Krkonoše where fir trees are not present within 4 km to 22% in fir-dominated woodland of the Roztocze, providing evidence of strong underrepresentation of fir in the pollen deposition. Application of these percentage thresholds to the Słone and Bezedna pollen diagrams indicates that occurrence of fir in the region is possible from 3.5 cal ky BP onwards, though the evidence is not decisive. In the Šumava, a low representation of fir pollen (1–2%) reflecting presence of scattered fir trees was detected as early as ca. 7.0 cal ky BP.

Presence of UV filters in surface water and the effects of phenylbenzimidazole sulfonic acid on rainbow trout (Oncorhynchus mykiss) following a chronic toxicity test

UV filters belong to a group of compounds that are used by humans and are present in municipal waste-waters, effluents from sewage treatment plants and surface waters. Current information regarding UV filters and their effects on fish is limited. In this study, the occurrence of three commonly used UV filters - 2-phenylbenzimidazole-5-sulfonic acid (PBSA), 2-hydroxy-4-methoxybenzophenone (benzophenone-3, BP-3) and 5-benzoyl-4-hydroxy-2-methoxy-benzenesulfonic acid (benzophenone-4, BP-4) - in South Bohemia (Czech Republic) surface waters is presented. PBSA concentrations (up to 13μgL(-1)) were significantly greater than BP-3 or BP-4 concentrations (up to 620 and 390ngL(-1), respectively). On the basis of these results, PBSA was selected for use in a toxicity test utilizing the common model organism rainbow trout (Oncorhynchus mykiss). Fish were exposed to three concentrations of PBSA (1, 10 and 1000µgL(-1)) for 21 and 42 days. The PBSA concentrations in the fish plasma, liver and kidneys were elevated after 21 and 42 days of exposure. PBSA increased activity of certain P450 cytochromes. Exposure to PBSA also changed various biochemical parameters and enzyme activities in the fish plasma. However, no pathological changes were obvious in the liver or gonads.

Architektura a ideologie. Výchovné instituce Adolfa Hitlera v protektorátu Čechy a Morava a v Říšské župě Sudety

This article examines the architecture of the Nazi regime in two occupied cities of Czechoslovakia, Praha/Prag and Jihlava/Iglau (the latter being one of the traditionally German-speaking island in the bohemia country), and focuses specifically on the process by which Hitler youth organisations (Hitlerjugend) in case of ‘education’ and indoctrination of youth were or were not successfully established in these cities. As comparison, he takes the political-administrative centres of the Sudeten Reichsgau, Ústí/Aussig, Opava/Troppau, Karlovy Vary/Karlsbad and Liberec/Reichenberg. Drawing on Czech and German archive materials, the extensive body of modern analytical literature, and propagandist literature from the period studied, the author examines the extent to which architecture served as a projection screen for Fascist propaganda in the Occupied Eastern territories. He describes the role played by the Reichsstelle für Raumordnung and shows how the Reich’s propagandist objectives came to be reflected in a high specific typology and stylistic lexicon/configuration for the architecture of Hitler youth hostels and homes He examines the process by which these organisations were powerful implanted into the space of occupied Czechoslovakia (and Sudeten) too, a topic that has not yet been addressed in (art) history too. The building projects developed for the Protectorate (published here for the first time) and managed by the Reich’s Hitler Youth Leadership in Berlin (Kulturamt, Reichsjugendführung, RJF, Abteilung HJ) reveal the ties that existed between the construction authorities in the Reich and the Protectorate, including the Planning Committee for the City of Prague. The author asks how many German and Czech architects participated for their own profit in the Nazi system, and for future research raises the hitherto taboo question of guilt and collaboration with the Nazis and the perception of this phenomenon in art history, i.e. the measure of active cooperation of not just German but also Czech architects who contributed to the planning and implementation of projects and thereby unequivocally had a hand in consolidating the totalitarian regime and de facto in the forced „Germanification” of their own people under occupation.

Wieczna kobiecość i emancypacja kobiet: obraz kobiecości w twórczości Karoliny Světlej

To nie przypadek, że wyrażenie „wieczna kobiecość" ukute przez Goethego zbiega się w czasie z pierwszymi zachodnimi próbami emancypacji kobiet. W chwili, kiedy model kobiety istniejącej tylko w zależności od mężczyzny zaczyna być kwestionowany, kategoria wiecznej kobiecości pozwala ponownie potwierdzić ten model, wypełniając go pozytywnymi wartościami. Naturą kobiety jest być uległą i oddaną, a te cechy sprawiają, że kobieta jest depozytariuszem wszelkiej potencjalnej zbawczej łaski. Tak w Fauście Goethego, przypada Małgorzacie, dziewczynie naiwniej, niewinnej, niewykształconej i bez własnej woli, wykupić Fausta siłą swojej miłości. Wszystko dzieje się tak, jakby pozytywna kodyfikacja właściwości kobiet dzięki kategorii wiecznej kobiecości służyła tylko lepszemu ukryciu rzeczywistości ich ucisku; feministki jednak nie dają się zwieść: ideały popierane przez kategorię wiecznej kobiecości są a priori niezgodne z emancypacją kobiet. Karolina Světlá, jedna z najważniejszych postaci w walce o zrównanie praw między mężczyznami i kobietami w Czechach w XIX wieku, wykorzystywała przecież intensywnie w swojej literackiej twórczości ten model kobiety, która poświęca się dla kochanego mężczyzny i tym samym udaje się jej go "podciągnąć do góry" ("hinan zu ziehen", Goethe) oraz dać mu dostęp do "nieskończoności", "nieśmiertelności" i "wieczności". Czy jej teoretyczne pisma i jej działalność na rzecz emancypacji kobiet zaprzeczałyby jej tekstom literackim, na pierwszy rzut oka tak konwencjonalnym? W tym wykładzie podejmuję próbę odpowiedzi na to pytanie uważną lekturą jednego z jej najbardziej faustowskich opowiadań, mianowice "Czarna dziewanna".

Polonofilizm i polskość wśród czeskich emancypantek w drugiej połowie XIX wieku: przykład Karoliny Světlej

The awakening of national consciousness went hand in hand in Bohemia with an anxiety about national disappearance. In this context, the recourse to Pan-Slavism was for the Czechs a way to encourage themselves through the idea of belonging to a great Slavic world, while the Slavic Congress organized in Prague in 1848 was an attempt to realize this ideal. The Congress was a failure from the political point of view, but it did have some socio-cultural repercussions: notably, it served as a pretext for the advancement of women's issues in Bohemia. It is indeed in the wake of the Congress that Honorata z Wiśniowskich Zapová, a Polish women settled in Prague after her marriage to a Czech intellectual, founded, under the guise of collaboration between all Slavic women, the first women's association, as well as a (very short-lived) Czech-Polish institute, where Czech, as well as Polish girls, could get a quality education in their mother tongue. Honorata was undoubtedly the source of the polonophilia wind that seemed to blow over the Czech emancipation movement in the second half of the nineteenth century. In particular, Karolina Světlá showed in her Memoirs a great recognition for Honorata's efforts in matters of emancipation and education, and explicitly took up the challenge launched by the latter in founding another women's association and in inaugurating a school for underprivileged girls. But the tribute Světlá paid to Honorata is even more evident in her literary work, where Poland and the Polish woman (who often wears Honorata's features) play a significant role (see for example her short novel Sisters or her story A Few Days in the Life of a Prague Dandy). Světlá was probably the Czech feminist writer who, in her activities and in her work, relied most strongly on the Polish woman as a model for the Czech woman. However, she wasn't alone. In general, it was a characteristic of the Czech feminist movement of the second half of the nineteenth century to have recourse to the Polish woman and to Poland as a landmark for comparison and as a goal to be achieved.