Nodulation (root nodule formation) in legume roots is initiated by the induction of cell divisions and formation of root nodule primordia in the plant root cortex, usually in front of the... Show moreNodulation (root nodule formation) in legume roots is initiated by the induction of cell divisions and formation of root nodule primordia in the plant root cortex, usually in front of the protoxylem ridges of the central root cylinder. We isolated a factor from the central cylinder (stele) of pea roots which enhances hormone-induced cell proliferation in root cortex explants at positions similar to those of nodule primordia. The factor was identified as uridine. Uridine may act as a morphogen in plant roots at picomolar concentrations. Show less
This book ('The reliance principle and contractual liability: an inquiry into the dogmatics of contract law') aims to be a contribution to the field of civil law and legal theory. lts central theme... Show moreThis book ('The reliance principle and contractual liability: an inquiry into the dogmatics of contract law') aims to be a contribution to the field of civil law and legal theory. lts central theme is the question whether it is possible to give an alternative foundation of contractual liability, given the fact that the so called reliance principle' ('Vertrauensprinzip') does not meet the standards of legal dogmatics in an appropriate manner. Thus it should be stressed that this book is not only concerned with the role of the reliance principle as a basis of liability in contemporary law, but also with the character of (continental-European) civil law itself. The nine chapters of the book can be read as one elaborated argument on the desired foundations of contract law. Show less
The biochemical isolation of pure and active proteins or chlorophyll protein complexes has been crucial for elucidating the mechanism of photosynthetic energy conversion. Most of the proteins... Show moreThe biochemical isolation of pure and active proteins or chlorophyll protein complexes has been crucial for elucidating the mechanism of photosynthetic energy conversion. Most of the proteins involved in this process are embedded in the photosynthetic membrane. The isolation of such hydrophobic integral membrane proteins is not trivial, and involves the use of detergents often combined with various time-consuming isolation procedures. We have applied the new procedure of perfusion chromatography for the rapid isolation of photosynthetic membrane proteins. Perfusion chromatography combines a highly reactive surface per bed volume with extremely high elution flow rates. We present an overview of this chromatographic method and show the rapid isolation of reaction centres from plant Photosystems I and II and photosynthetic purple bacteria, as well as the fractionation of the chlorophyll a/b-binding proteins of Photosystem I (LHC I). The isolation times have been drastically reduced compared to earlier approaches. The pronounced reduction in time for separation of photosynthetic complexes is convenient and permits purification of proteins in a more native state, including the maintainance of ligands and the possibility to isolate proteins trapped in intermediate metabolic or structural states. Show less
The lowest tripler state, T-0, of all-trans-tetradecahexaenal has been investigated by means of electron-spin-echo spectroscopy in a magnetic field and in zero field. The directions of the... Show moreThe lowest tripler state, T-0, of all-trans-tetradecahexaenal has been investigated by means of electron-spin-echo spectroscopy in a magnetic field and in zero field. The directions of the principal axes and the eigenvalues of the fine-structure tensor have been determined. The tripler state corresponds to a pi pi* excitation. In zero field, T-0 is populated predominantly through the upper spin sublevel which is found to decay fastest. Comparison of the relative energies and the decay rates of the sublevels of T-0 with those obtained previously for shorter polyenals reveals that both the zero-field splitting and the logarithm of the decay rates are inversely proportional to the total number of double bonds. Show less
The effect of redox-inactive cationic and anionic paramagnetic chromium(III) complexes on the H-1 NMR spectrum of the reduced type 1 blue copper protein amicyanin, AmCu1, from Thiobacillus versutus... Show moreThe effect of redox-inactive cationic and anionic paramagnetic chromium(III) complexes on the H-1 NMR spectrum of the reduced type 1 blue copper protein amicyanin, AmCu1, from Thiobacillus versutus has been studied as a means of defining sites for association at the protein surface. With [Cr(CN)(6)](3-) two sites are detected, one at the adjacent hydrophobic patch close to the exposed imidazole of the co-ordinated His-96, and the other at Phe-92 which has Lys-59, Lys-60, Arg-69 and Arg-100 in close proximity and is adjacent to the active site-co-ordinated Cys-93. In contrast, the cationic complexes [Cr(NH3)(6)](3+) and [Cr(en)(3)](3+) (en = ethane-2,2-diamine) cause no significant line broadening and no preferred sites for association are detected. Kinetic stopped-flow studies on the competitive inhibition by [Cr(CN)(6)](3-) of the [Fe(CN)(6)](3-) oxidation of AmCu1 indicate that [Fe(CN)(6)](3-) reacts at two sites, one of which is inhibited by [Cr(CN)(6)](3-) and the other is unaffected by [Cr(CN)(6)](3-). It is suggested that the first of these corresponds to reaction at the Phe-92 site, contributing 25% to the reaction, and the second to reaction at His-96. Therefore, in its reaction with [Fe(CN)(6)](3-) amicyanin has adjacent and remote binding sites. Show less
