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THELOHANIA-CAPILLATA N-SP (MICROSPORA, THELOHANIIDAE) - AN ULTRASTRUCTURAL-STUDY WITH REMARKS ON THE TAXONOMY Of THE GENUS THELOHANIA HENNEGUY, 1892

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ARCHIV fUR PROTISTENKUNDE 1983年第1期127卷 21-46页

作者： LARSSON, R Department of Zoology University of Lund Lund Sweden

T. capillata sp. nov. is described from larvae of the blackfly Odagmia ornata (Meigen, 1818), collected in a small stream in the south of Sweden. Infection was restricted to the adipose tissue, which was transformed into a syncytial xenoma. The earliest stage observed was diplokaryotic merozoites, which mature directly into diplokaryotic sporonts. The 1st division of the sporont is a meiosis, identified by the occurrence of synaptonemal complexes, and it is usually followed by a mitotical division, resulting in a plasmodium with 8 single nuclei. The cytoplasm is further divided into 8 lobes which finally give rise to 8 rounded sporoblasts. Each sporoblast matures into a barrel-shaped spore, with a spore-wall composed of 3 layers, 280-350 nm thick. Most spores are octosporous microspores, dimensions 2.0-3.1 .times. 2.0-2.7 .mu.m in fixed preparations, but a small number of macrospores, 3.5-4.5 .times. 2.8-3.0 .mu.m, are produced in pansporoblasts with 4 spores. Both spore types with a single nucleus and a nearly identical fine structure. The anchoring disc is small and the straight part of the polar filament reaches the posterior pole of the spore. It is surrounded by a polaroplast composed of 2 structurally different parts. The anterior part is .apprx. 1/3 of the spore length, the posterior .apprx. 2/3. The polar filament is of approximately uniform thickness all over its length. In microspores the diameter is 120-140 nm, in macrospores it is slightly bigger, 125-150 nm. The polar filament of microspores is posteriorly arranged as 4-5 coils in a single layer close to the spore wall. The angle of tilt of the 1st filament coil is .apprx. 45 degrees. In macrospores the posterior part of the filament is arranged as 8 irregularly stacked coils. Sporogony occurs in a pansporoblast transversed by a fibrous material continuous from the spore wall to the pansporoblast membrane, which has a hair-like fibrous appearance. The relationship of the new species to other species of

关键词： Thelohania capillata sp. nov. Protozoa Microspora Ultrastructure Taxonomy Simuliidae AD anchoring disc C chromatin CE central element CO cortical layer CP centriolar plaque CK chromosome D diplokaryon EM electron-dense material EN endospore EX exospore f fibrillar layer G granular layer H holotype LE lateral element M merozoite MG metabolic granule MS mature spore N nucleus NL nucleole P polaroplast PA anterior region of the polaroplast Pf polar filament PL plasmalemma PM pansporoblast membrane PP posterior region of the polaroplast PS posterosome PV posterior vacuole R ribosomes SB sporoblast SP sporont T tubule IJ unit membrane V vesicle

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THE SIGNIfICANCE Of THE KINETIC-ANALYSIS Of fLUORESCENCE INDUCTION IN DCMU-INHIBITED CHLOROPLASTS IN TERMS Of PHOTOSYSTEM-2 CONNECTIVITY AND HETEROGENEITY

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fEBS LETTERS 1983年第1-2期160卷 177-181页

作者： HODGES, M BARBER, J ARC Photosynthesis Research Group Department of Pure and Applied Biology Imperial College London SW7 2BB England

A study has been made on the slow component (β max ) of chlorophyll fluorescence induction curves exhibited by DCMU-inhibited pea thylakoids. In the absence of high levels of screening cations, β max is high and the fluorescence yield low, while the addition of K + , Mg 2+ or Tris(ethylenediamine) cobaltic(III) cation (TEC 3+ ) decreases β max and increases fluorescence yield. These changes are inhibited when the thylakoids are fixed with glutaraldehyde. By comparing cation- and light-harvesting chlorophyll a/b -protein (LHCP) phosphorylation-induced changes it can be seen that β max correlates with changes in the overall kinetics of photosystem (PS) 2 photoreduction, as indicated from the normalised area over the induction curve (Anorm). When the plastoquinone (PQ) pool is chemically reduced by dithionite, prior to the initiation of the curve, both f o and f m are increased and the slow component removed. These observations are used to question the concept of two structurally distinct PS2 centres [Arch. Biochem. Biophys. (1978) 190, 523–530] and to discuss the use of β max in monitoring PS2 organisation.

关键词： Photosynthesis Chlorophyll fluorescence Induction curve Biphasic kinetics Membrane organisation Structural heterogeneity DCMU, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea LHCP, light-harvesting chlorophyll a/b -protein complex PS, photosystem Q, primary acceptor of photosystem 2 f m , maximum fluorescence f o , initial fluorescence f v , f m − f o A max , unnormalised area over induction curves A norm , normalised A max

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METRIZATION Of fPP-SPACES

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TOPOLOGY AND ITS APPLICATIONS 1983年第1期15卷 7-10页

作者： BENNETT, HR Department of Mathematics Texas Tech University Lubbock TX 79409 USA

A Hausdorff space each subspace of which is a paracompact p -space is an f pp -space. A space X is a closed hereditary Baire space if each closed subspace of X is a Baire space. Using a delicate theorem of Z. Balogh i... 详细信息

关键词： 54B35, 54D18 f pp -space paracompact p -space Baire space metrizable

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A COMPARISON BETWEEN CATION AND PROTEIN-PHOSPHORYLATION EffECTS ON THE fLUORESCENCE INDUCTION CURVE IN CHLOROPLASTS TREATED WITH 3-(3,4-DICHLOROPHENYL)-1,1-DIMETHYLUREA

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BIOCHIMICA ET BIOPHYSICA ACTA 1983年第1期722卷 214-218页

作者： HORTON, P BLACK, MT UNIV SHEFFIELD DEPT BIOCHEM SHEFFIELD S10 2TN S YORKSHIRE ENGLAND UNIV SHEFFIELD ARC PHOTOSYNTH RES GRP SHEFFIELD S10 2TN S YORKSHIRE ENGLAND

fluorescence induction curves in chloroplasts phosphorylated by the thylakoid protein kinase activated at low light intensity and high chlorophyll concentration were measured. At 5 mM Mg2+, phosphorylation did not preferentially quench variable fluorescence. At 1 mM, preferential quenching of variable fluorescence occurred, indicating a 2nd effect of phosphorylation at low Mg2+ (Horton and Black 1982). Comparison of the extent of fluorescence decrease and the resulting ratio of variable to maximum fluorescence after phosphorylation and after lowering Mg2+ concentration demonstrated a difference between these 2 mechanisms of lowering of fluorescence. The significance of these results in terms of how phosphorylation may alter membrane organization is discussed.

关键词： Chlorophyll fluorescence fluorescence induction Thylakoid membrane Protein kinase Light-harvesting chlorophyll-protein complex (Pea chloroplast) PS photosystem DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea Q the quencher of fluorescence and primary acceptor of PS II f 0 initial fluorescence level recorded when Q is fully oxidized f m final or maximal fluorescence level recorded when Q is fully reduced f v f m − f 0 LHCP light-harvesting chlorophyll-protein complex associated with PS II

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POSSIBLE INVOLVEMENT Of NADPH-CYTOCHROME-P450 REDUCTASE AND CYTOCHROME-B5 ON BETA-KETOSTEAROYL-COA REDUCTION IN MICROSOMAL fATTY-ACID CHAIN ELONGATION SUPPORTED BY NADPH

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fEBS LETTERS 1983年第1期155卷 11-14页

作者： NAGAO, M ISHIBASHI, T OKAYASU, T IMAI, Y HOKKAIDO UNIV SCH MED DEPT BIOCHEM SAPPORO HOKKAIDO 060 JAPAN

The chain elongation products from [2-14C]malonyl-CoA and palmitoytl-CoA by rat liver microsomes initiated by NADPH were found mainly to be 18:1 and 18:0. When anti-NADPH-cytochrome P450 reductase or anti-cytochrome b5 immunoglobulin G were included in this system, not only was the overall chain elongation significantly suppressed, but also a new radioactive product, which was identified as 2-heptadecanone derived from an intermediate beta-ketostearate, is accumulated depending upon the amounts of IgG added. These results suggest that NADPH-cytochrome P450 reductase and cytochrome b5 participate in the conversion from beta-ketostearoyl-CoA to beta-hydroxystearoyl-CoA, which is the first reductive step of the microsomal chain elongating system.

关键词： Immunochemical evidence Cytochrome b 5 f pT Microsome fatty acid Chain elongation

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PHOTOSYNTHETIC ATP fORMATION fROM ADDED ADP IN THE ABSENCE Of INORGANIC-PHOSPHATE BY CHROMATOPHORES fROM RHODOPSEUDOMONAS-PALUSTRIS, RHODOPSEUDOMONAS-SPHEROIDES AND RHODOSPIRILLUM-RUBRUM

PHOTOBIOCHEMISTRY AND PHOTOBIOPHYSICS

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PHOTOBIOCHEMISTRY AND PHOTOBIOPHYSICS 1983年第5-6期6卷 317-327页

作者： MULLER, H NEUfANG, H KNOBLOCH, K Institut fur Botanik und Pharmazeutische Biologie der Universitat Erlangen - Nurnberg Schlossgarten 4 D - 8520 Erlangen F. R. G

Chromatophores from Rhodopseudomonas palustris, Rhodopseudomonas spheroides and Rhodospirillum rubrum transphosphorylate as a function of membrane-bound Rf, medium-ADP in the light without added inorganic phosphate to ATP and AMP. This phosphorylation occurs at a rate 50-60 times lower when compared to ATP formation in the presence of P,. That this transphosphorylation is catalyzed by the membrane-bound coupling factor-ATPases (EC 3.6.1.3), and not by the conventional adenylate kinases (EC 2.7.4.3) contaminating the chromatophore preparations is supported by the following evidence: (1) ATPases and adenylate kinases have been isolated and the purification procedure has the advantage of several physical differences to separate these enzymes. The adenylate kinases could not be detected in the purified ATPase preparations by polyacrylamide gel electrophoresis. (2) The adenylate kinases have been solubilized completely from the chromatophores by repeated washings with Tris-HCl buffer, pH 8.0, whereas the ATPases remained on the membranes. (3) Under no conditions could the purified ATPases produce ATP from added ADP. However, the purified solubilized and membrane-bound ATPases have been able to hydrolyze ADP to AMP and inorganic phosphate as judged from thin-layer chromatography and high-performance liquid chromatography. (4) Comparative studies including inhibitors have shown that the washed chro- matophores are capable of photophosphorylating medium-ADP without added inorganic phosphate in the presence of P 1 ,P 5 -di(adenosine-5')pentaphosphate which inhibits completely the purified adenylate kinases. Conversely, the chromatophores have been prevented from synthesizing ATP in the presence of the membrane-bound ATPase inhibitors oligomycin, Dio-9 and N, TV'-dicyclohexylcarbodiimide. from these results it becomes conceivable that under conditions where inorganic phosphate is the limiting factor in phosphorylation, ADP can be cleaved in a first step by the membrane-bound

关键词： photosynthesis phosphorylation adenylate kinase Rhodopseudomonas Rhodospirillum BChl bacteriochlorophyll Rf 1 f r ATPases from Rhodopseudomonas and Rhodospirillum species

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THE BIMOLECULAR DECAY-RATES Of THE fLAVOSEMIQUINONES Of RIBOfLAVIN, fMN AND fAD

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BIOCHIMICA ET BIOPHYSICA ACTA 1983年第1期723卷 78-82页

作者： ANDERSON, Rf Cancer Research Campaign Gray Laboratory Mount Vernon Hospital Northwood Middlesex HA6 2RN U.K.

The bimolecular decay rates (2k) of the flavosemiquinones .**GRAPHIC**. of riboflavin, fMN and fAD were determined using pulse radiolysis. The rates (defined as .**GRAPHIC**. = .**GRAPHIC**. for the neutral flavosemiquinones at zero ionic strength and pH 5.9 are (in units of mol-1 .cntdot. dm3 .cntdot. s-1):(1.2 .+-. 0.1) .cntdot. 109, (5.0 .+-. 0.2) .cntdot. 108 and (1.4 .+-. 0.1) .cntdot. 108;and for the anionic flavosemiquinones at pH 11.2 (5.4 .+-. 0.9) .cntdot. 108, (4.5 .+-. 0.3) .cntdot. 107 and (8.5 .+-. 1.3) .cntdot. 106, respectively. The kinetic salt effect was used to formulate rate equations for each flavin to adjust for ionic strength effects.

关键词： Riboflavin fMN fAD flavosemiquinone Bimolecular decay Pulse radiolysis f oxidised flavin fH · f ⨪ flavosemiquinone fH 2 fH − fully reduced flavin

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PURIfICATION AND PROPERTIES Of AN ENDONUCLEASE fROM NUCLEI Of TOBACCO CELL-CULTURES

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ZEITSCHRIfT fUR PfLANZENPHYSIOLOGIE 1983年第4期109卷 291-300页

作者： SZOPA, J BOCHER, M WAGNER, KG GESELL BIOTECHNOL FORSCH MBH MOLEK BIOL ABT D-3300 Braunschweig GERMANY

Extraction of nuclei prepared from N. tabacum cell cultures, chromatography on DEAE-cellulose and DNA-cellulose and gel filtration resulted in a homogenous protein (MW = 32,000) with endonuclease activity. The enzyme cleaves Escherichia coli DNA at only a few sites and transforms closed superhelical plasmid DNA into circular relaxed molecules and the latter, in a slow reaction, into the linear form. It has very little, if any, exonucleolytic activity nor nucleotidase activity and is not inhibited by ATP. A recently described plant nuclease inhibitor inhibits the endonuclease action in a 1:1 stoichiometry. Metal ions (Na+, Mg2+ and Zn2+) influence the degradation of plasmid DNA in a different way. The mode of the enzyme action and its possible physiological role are discussed.

关键词： Nicotiana tabacum plant nucleases nuclear enzymes cell suspensions cultures PhMeSO 2 f Phenylmethylsulfonyl fluoride DTT Dithiothreitol

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THE MECHANISM Of AMINE INHIBITION Of THE PHOTOSYNTHETIC OXYGEN EVOLVING COMPLEX - AMINES DISPLACE fUNCTIONAL CHLORIDE fROM A LIGAND SITE ON MANGANESE

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fEBS LETTERS 1983年第2期162卷 339-343页

作者： SANDUSKY, PO YOCUM, Cf UNIV MICHIGAN DIV BIOL SCIANN ARBORMI 48109 UNIV MICHIGAN DEPT CHEMANN ARBORMI 48109

Amines inhibit photosynthetic oxygen evolution by binding to manganese in the oxygen evolving complex. This inhibition is more effective if chloride is absent. Steady-state kinetic analyses show that ammonia and chloride compete for the same site in the oxygen evolving complex; inhibition of oxygen evolution by either chloride depletion or by ammonia addition induces Signal II f , which saturates at high microwave power. These data indicate that chloride is bound at the manganese site in the oxygen evolving complex. We propose that the anion functions as a bridging ligand mediating electron transfer between manganese atoms and perhaps also between manganese and Z, the primary donor to P680.

关键词： Photosystem II Oxygen evolution Amine inhibition Chloride Bridging ligand Signal II f OEC oxygen evolving center PS photosystem Chl chlorophyll DCBQ 2,5-dichloro- p -benzoquinone

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PURIfICATION AND PROPERTIES Of A MANGANESE-DEPENDENT ENDONUCLEASE fROM TOBACCO CELL-CULTURES

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ZEITSCHRIfT fUR PfLANZENPHYSIOLOGIE 1983年第4期111卷 341-348页

作者： SZOPA, J SZMIDZINSKI, R WAGNER, KG GESELL BIOTECHNOL FORSCH MBH D-3300 BRUNSWICK FED REP GER

from suspension cultured cells of N. tabacum a Mn-dependent DNA endonuclease was purified to homogeneity with a molecular weight of 24,000 in SDS [sodium dodecylsulfate] gel electrophoresis. It has a pH optimum of 7.0 and a temperature optimum of ***. C. The enzyme does not digest RNA or synthetic polyribonucleotides;it has no exonucleolytic and nucleotidase activity and is inhibited by nucleoside triphosphates in the mM range. The tobacco endonuclease cleaves heat denatured DNA slightly faster than native DNA;however, in both cases the products are large fragments 3-4 kb [kilobase] in size. It is shown with native DNA, that the mode of action of the enzyme is to generate single-strand nicks probably at AT-rich clusters. The present enzyme differs from the endonuclease recently purified from nuclei of the same source (Szopa et al., 1983) by its molecular weight, the metal ion-dependency, pH-optimum, inhibition by ATP and the mode of action especially with superhelical DNA. The present enzyme is copurified with RNA-polymerase I.

关键词： Nicotiana tabacum cell suspension cultures plant nucleases DTT Dithiothreitol PheMeSO 2 f Phenylmethylsulfonyl fluoride TCA Trichloroacetic acid

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