| | 2 | Author
| Ruth Hracky, Jürgen Soll | Requires cookie* | | | Title
| Protein Phosphorylation — Dephosphorylation in the Cytosol of Pea Mesophyll Cells  | | | | Abstract
| Soluble protein kinase and protein phosphatase activities were localized in the cytosol of pea mesophyll cells using protoplasts fractionation techniques. The molecular weights of the phos-phorylated cytosolic proteins, as determined by polyacrylamide gel electrophoresis, were 68, 55, 46, 38, 36, 30, 22 and 12 kDa. Histone and, to a much lesser extent, casein but not phosvitin were accepted as exogenous substrates. In every case serine served as acceptor amino acid for the phosphate residue. The protein phosphorylation activity had an alkaline pH optimum, and showed no response to varying Mg2+, Ca2+, Pn cyclo-AMP or calmodulin concentrations. The kinase activity was competitively inhibited by ADP and pyrophosphate with apparent K t values of 0.5 and 0.17 m M , respectively. High ATP concentrations (1 -4 m M) resulted in a strong decrease of radioactivity in the ,2P labeled proteins. It is proposed that the ratio of protein phosphorylation to protein dephosphorylation is regulated by the ATP to ADP ratio in the cytosol. | | | |
Reference
| Z. Naturforsch. 41c, 856 (1986); received July 9/August 5 1986 | | | |
Published
| 1986 | | | |
Keywords
| Protein Kinase, Protein Phosphatase, Cytosol, Protoplasts, Pisum sativum | | | |
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| | | | | TEI-XML for
| default:Reihe_C/41/ZNC-1986-41c-0856.pdf | | | | Identifier
| ZNC-1986-41c-0856 | | | | Volume
| 41 | |
| 3 | Author
| Kohki Akiyamaa, Kazuyoshi Kawazua, Akio Kobayashib | Requires cookie* | | | Title
| Partially N-Deacetylated Chitin Oligomers (Pentamer to Heptamer) are Potential Elicitors for (+)-Pisatin Induction in Pea Epicotyls | | | | Abstract
| Oligomers (dimer to heptamer) of chitosan and their partially/completely N-acetylated derivatives were examined for (+)-pisatin-inducing activities in pea epicotyl elicitor assay at concentrations ranging from 6.25 to 100 j.ig/ml. The structures of the oligomers were analyzed by 'H NM R and M A L D I TOF MS spectrometers. The chitosan oligomers from dimer to tetramer were inactive, while the pentamer exhibited a moderate activity at 100 |ig/ml. The hexamer showed a pronounced activity at 100 |ag/ml, whereas the oligomer had no activity at the higher concentrations. Although the chitosan heptamer induced a moderate amount of (+)-pisatin (ca. 60 j.ig/g fr. wt.) at 50 (.ig/ml, the oligomer did not elicit pisatin formation at 100 |ig/ml. The dimer to tetramer of both partially N-deacetylated chitin (DAC) and chitin were totally inactive. The DAC pentamers (d.a. 31%, 52%), DAC hexamers (d.a. 26%, 41%), and DAC heptamers (d.a. 26%, 36%) exhibited significant elicitor activities at lower concen trations (6.25-25 [.ig/ml) than the native chitosan oligomers. The chitin pentamer to heptamer had weak or no activity. Both glucosamine and N-acetylglucosamine were inactive in the assay. These facts suggest that the DAC pentamer to heptamer may act as elicitors for pisatin induction in pea-fungus interactions. | | | |
Reference
| Z. Naturforsch. 50c, 391—397 (1995); received January 4/January 15 1995 | | | |
Published
| 1995 | | | |
Keywords
| Elicitor, Chitosan, Chitin, Phytoalexin, Pisum sativum | | | |
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| default:Reihe_C/50/ZNC-1995-50c-0391.pdf | | | | Identifier
| ZNC-1995-50c-0391 | | | | Volume
| 50 | |
| 4 | Author
| F. Rank Terjung, K. Arlheinz, M. Aier | Requires cookie* | | | Title
| Nonphotochemical Quenching of Chlorophyll Fluorescence in Higher Plant Leaves Studied by Delayed Fluorescence Decay Measurements | | | | Abstract
| Delayed chlorophyll fluorescence decay measurements on the second time scale were ap plied to investigate the state of photosystem II under different photosynthetic conditions. Leaves adapted to high and low light intensities were used to study the effects of nonphoto chemical quenching (energy quenching) on the photosynthetic state. 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCM U)-treated leaves were used to characterize the photosynthetic state in the absence of a transthylakoid ApH, dithiothreitol (D TT)-treated leaves in the absence of the xanthophyll zeaxanthin. The fast decay components were the most affected by energy quenching as indicated by increased decay times. The slowest decay com ponent was hardly affected, neither in amplitude nor in decay time. The measurem ents indicate a relaxation of energy quenching on the second time scale and the absence of damages in the electron transfer chain of PS II. The constant decay times of the DTT-treated leaf, com parable to those of the DCM U-treated leaf, indicate the obligatory role of zeaxanthin for most of the detected energy quenching. | | | |
Reference
| Z. Naturforsch. 53c, 27—32 (1998); received October 9/October 31 1997 | | | |
Published
| 1998 | | | |
Keywords
| Delayed Fluorescence, Energy Quenching, Pisum sativum, Xanthophyll Cycle | | | |
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| default:Reihe_C/53/ZNC-1998-53c-0027.pdf | | | | Identifier
| ZNC-1998-53c-0027 | | | | Volume
| 53 | |
| 5 | Author
| Christine Schindler, Ruth Hracky, Jürgen Soll | Requires cookie* | | | Title
| Protein Transport in Chloroplasts: ATP is Prerequisit | | | | Abstract
| The energy requirem ent for protein transport into chloroplast was assayed under conditions that perm it to distinguish whether the posttranslational translocation is dependent on A TP or w hether a m em brane potential across the chloroplast envelope can drive this transport event. A m em brane potential is not required for translocation. A TP can support protein transport in the presence of protonophores and ionophores. Non-hydrolyzable A TP analogues and G TP, CTP, U T P cannot serve as ATP substitutes. Translocation could be observed when an A TP generating system was used to supply ATP. In contrast ATP degrading systems completely abolished translocation. The inner envelope mem brane localized ATP-ase is probably not involved in the transport event. The results suggest that ATP is needed at the outer chloroplast envelope. Inhibition of protein transport by A D P , pyrophosphate and NaF is studied and its con sequences discussed. | | | |
Reference
| Z. Naturforsch. 42c, 103 (1987); received August 26 1986 | | | |
Published
| 1987 | | | |
Keywords
| Protein T ransport, ATP-Hydrolysis, Chloroplasts, Envelope, Pisum sativum | | | |
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| default:Reihe_C/42/ZNC-1987-42c-0103.pdf | | | | Identifier
| ZNC-1987-42c-0103 | | | | Volume
| 42 | |
| 6 | Author
| N. Orbert, G. Rotjohann, David Messdaghi, Wolfgang Kowallik | Requires cookie* | | | Title
| Oxygen Uptake during Photosynthesis of Isolated Pea Chloroplasts | | | | Abstract
| Mass spectrometric analysis of the gas exchange of illuminated leaflets of 10-14 d old pea seedlings revealed not only 160 2-liberation from photosynthetic H2160-splitting, but also uptake of ls0 2, applied to the gas phase of the reaction vessel. Isolated intact chloroplasts of such leaflets suspended in a medium containing N aH C 03 and glycerate 3-phosphate, on irradiation with blue (A. 448 nm) or red (X 679 nm) light also produced 160 2 from water oxidation and consumed 180 2 from the gas phase. The two reactions were saturated at the same quantum fluence rates. Uptake of 18oxygen was not affected by inhibitors of mito chondrial respiration (alternative pathway included), such as rotenone (5 x l0 -5 m), antimycin A (5 x l0 ~6 m), KCN (10-3 m), SHAM (10-3 m), or propylgallate (10-3 m). It was, however, absent, when photosynthetic 16oxygen evolution was completely inhibited by DCMU (10-? m). DBMIB (10~5 m), assumed to prevent electron flow from plastoquinone pool to the cyto chrome ö6//-complex, suppressed photosynthetic oxygen evolution, but did not impair uptake of 180 2. A similar result was obtained at application of 4 x l0 _e; m antimycin A. The data are interpreted to show a drain off to molecular oxygen of light-excited electrons from the photosynthetic electron transport chain at the site of plastoquinone pool during photosynthesis. This corresponds to chlororespiration, originally described for Chlamydomo-nas in darkness by Bennoun (1982). It is discussed, whether 0 2-uptake during photosynthesis is an additional means for providing ATP for photosynthetic C 0 2-reduction by increasing the proton gradient across the thylakoid membrane. | | | |
Reference
| Z. Naturforsch. 54c, 209—219 (1999); received October 5/November 13 1998 | | | |
Published
| 1999 | | | |
Keywords
| Pisum sativum, Chlororespiration, 18Oxygen Consumption, Photophosphorylation, Intact Isolated Chloroplasts | | | |
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| default:Reihe_C/54/ZNC-1999-54c-0209.pdf | | | | Identifier
| ZNC-1999-54c-0209 | | | | Volume
| 54 | |
| 8 | Author
| Heinz-W Alter, Scheid, Adelheid Ehmke, Thomas Hartm | Requires cookie* | | | Title
| Plant NAD-Dependent Glutamate Dehydrogenase. Purification, Molecular Properties and Metal Ion Activation of the Enzymes from Lemna minor and Pisum sativum | | | | Abstract
| Glutamate dehydrogenase (L-glutamate: N A D + oxidoreductase (deaminating) EC 1.4.1.2) has been purified to homogeneity from Lemna minor and seeds o f Pisum sativum. As established by polyacrylamide gel electrophoresis the Pisum-enzyme constitutes a multiple pattern o f seven char ge isoenzymes whereas the Lemna enzyme shows one single protein band. Molecular weights of 230 000 were calculated for both enzymes by sedimentation equilibrium measurements (Pisum-enzyme]I and comparative gel filtration (Lemna-enzyme). Sodium dodecyl sulfate gel electropho resis and electron microscopic observations revealed that both enzymes are composed of four identical subunits (molecular weight 58 500) arranged in a tetraedric structure. The amino acid compositions of both enzymes are similar to those of various hexameric glutamate dehydrogen ases. The N-terminal amino acid of the Pisum-enzyme is alanine. Both enzymes require Ca2+ for maximal catalytic activity. For the Lemna-enzyme the K0.s values for Ca2+ are 22 /j.m (NADH-de-pendent reaction) and 4 piM (N A D +-dependent reaction), respectively. Ca2+ which to some extent can be replaced by Zn2+ does not affect the enzyme aggregation but seems to govern a reversible equilibrium between catalytically active and inactive enzyme forms. | | | |
Reference
| Z. Naturforsch. 35c, 213—221 (1980); received November 21 1979 | | | |
Published
| 1980 | | | |
Keywords
| Lemna minor, Pisum sativum, Glutamate Dehydrogenase, Purification, Molecular Properties, Me tal Ion Activation | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0213.pdf | | | | Identifier
| ZNC-1980-35c-0213 | | | | Volume
| 35 | |
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