A double ínductíon mechanism of Dl protein degradatíon in isolated photosystem 2 (PS2) core complexes and reaction centres is described, showing the existence of two potentíal sites for primáty cleavage. Donor side inhibition conditi- o n s (presence of electron acceptors but no electron donors and pH 8.0) trigger the hydrolysis of the Dl protein between the putatíve helices 1 and II on the lumenal side of the thylakoid membrane. This results in the generation of a C-terminal 24 kDa fragment. However, when the donor-side is actíve (presence of electron donors but no electron acceptors and pH 6.0, acceptor side inhibition conditions) both preparations are able to produce a N-terminal 23 kDa fragment, indicating cleavage between helices IV and V, on the stromal side of the membrane.
This paper analyses two lists of errors in the Waldesian cult, as contained in manuscripts I F 230 (from 1399, and its twin manuscript Mil II 58), as well as I F 707 (from the early 15th century). The list in manuscript I F 230 was compiled earlier, whereas the one from manuscript I F 707 is identical with the list included in manuscript No. 229 from the library in Pelplin. The comparison of the anti-heretic lists of errors from manuscripts I F 230 and I F 707, as well as the analysis of their contents, reveals similarities and leads to a conclusion that they both refer to writings by inquisitor Petrus Zwicker, while the list in I F 230 could have been even authored by him.
High (HI, 200 W m'^) and low (LI, 30 W m"^) irradiance treatments on the cells of cyanobactenum Synechococcus elongatus Nfig., var. thermalis Geitl. strain KOVROV 1972/8 were perfonned in the presence of chloramphenicol (CAP), and with addition of DCMU and hydroxylamine (HA), respectively, at growth (56 °C) and low (20 °C) temperatures, to distínguish allegedly different mechanisms of PS 2 photoinactivation (PS 2 PI). At both temperatures HI caused a decline of Fy and Hill reaction activity (HRA) followed by degradation of Dl and to a lesser extent also D2 protein. Fq increased slowly during irradiance at 56 while at 20 ®C it quickly rose to constant level. Degradation of proteins was slowed at a lower temperature. The presence of DCMU during photoinhibition significantly blocked the Fq rise and also prevented PS 2 protein degradation at both temperatures. The course of PS 2 PI under LI resembled tlmt, observed at HI, but changes were much slower. During irradiation of the cells, in which oxygen evolving complex (OEC) was impaired by HA, we observed: (/) at least a ten-fold faster decline of PS 2 electron transport activity than in the cells vňth fimctional OEC under the same conditions; (2) an extensive degradation not only of Dl and D2, but also of the apoprotein of chlorophyll-protein CP43 {ACP43y, (3) almost complete inhibition of PS 2 protein degradation in the presence of DCMU. Thus under all conditions tested in vivo which do not affect the fimction of OEC, the fimction of OEC, PS 2 PI proceeds via the acceptor side and a fimctional impairment of OEC is necessary for induction of the donor side mechanism. When OEC is impaired (e.g. by HA) this mechanism can come in action.
The paper studies the typology of the initials following the way of construction of their corpus in the mutual ties in the development – departing from the late antique, considering the Byzantine and Pre-Romanesque and Romanesque types. The modifications of the initials are studied together with the changes of their function in the decoration system and in the cultural-historical context. The contribution also studies the changes of the terminology connected with the typology of the initials.
The paper studies the typology of the initials following the way of construction of their corpus in the mutual ties in the development – departing from the late antique, considering the Byzantine and Pre-Romanesque and Romanesque types. The modifications of the initials are studied together with the changes of their function in the decoration system and in the cultural-historical context. The contribution also studies the changes of the terminology connected with the typology of the initials.
The paper studies the typology of the initials following the way of construction of their corpus in the mutual ties in the development – departing from the late antique, considering the Byzantine and Pre-Romanesque and Romanesque types. The modifications of the initials are studied together with the changes of their function in the decoration system and in the cultural-historical context. The contribution also studies the changes of the terminology connected with the typology of the initials.
The paper is engaged with a definition of the typolotgy and modifications fo the caligraphic initials, compared with the typology of painted initials, and also with a comparative study of the terminoloty used in different languages for the specific compositions. The interest is also focused on relations among countries, regions and workshops that participated in the transformations of the caligrafic initials. The subject is studied on a broad period, from the Late Antiquity till the 16th century, but without a typology of fleuronée, only compositions of the body of the initials have been taken into consideration.
Incubation of maize NADP-malic enzyme with tetranitromethane (TNM) resulted in a total loss of enzyme activity. The loss of enzyme activity was not observed at pH 6.3 but at pH 8.0. NADP-malic enzyme was inactivated to almost 90 % by incubation with an 80-fold molar excess of TNM for 5 min at 30 °C. The substrate malate or Mg2+ alone gave no protection, while NADP provided considerable protection. NADP in the presence of malate and Mg2+ totally protected the enzyme activity, suggesting that tyrosine residue may be located at or near the active site of maize NADP-malic enzyme. The spectral analysis of the modified enzyme indicated that modification of at least one tyrosine residue per subunit resulted in complete loss of the enzyme activity. The fluorescence study of unmodified and modified enzymes postulated that essential tyrosine residue at maize NADP-malic enzyme is possibly involved in malate binding. and S. R. Rao, B. G. Kamath, A. S. Bhagwat.
This article is focused on opinions that the literary historian and Custodian of the Prague Imperial-Royal University Library (now the National Library of the Czech Republic) Josef Truhlář (1840-1914) had on Manuscripts of Dvůr Králové and Zelená Hora. Initially, he had been convinced of the authenticity of the Manuscripts, but after Gebauer´s groundbreaking article questioning their authenticity published in the Athenaeum journal in February 1886, he re-evaluated his older opinions and published a series of articles in this journal denying the authenticity of the Manuscripts. These articles were focused on suspicious finding circumstances of these allegedly old monuments, parallels in their texts with literary works from the early 19th century and on other contemporary forged manuscripts.
Influence of moderate chilling stress on vascular bundle sheath cell (BSC) and especially mesophyll cell (MC) chloroplasts of mature maize leaves was studied by electron microscopy and stereology. Plants of two inbred lines of maize, differing in their photosynthetic activity, and their F1 hybrids were cultivated during autumn in heated or unheated glasshouse. Generally, chilling temperatures resulted mainly in the decrease in stereological volume density (VD) of both granal and intergranal thylakoids of MC chloroplasts, while the ratio of granal to all thylakoids (granality) was less affected. The VD of peripheral reticulum and plastoglobuli usually increased after cold treatment of plants. The volume of MC chloroplasts usually increased under chilling stress, the shape of the chloroplasts changed only slightly. The ultra-structure of chloroplasts differed between individual genotypes; chilling-stressed hybrid plants showed positive heterosis particularly in the granal thylakoids' VD of MC chloroplasts. and J. Kutík ... [et al.].