Mg-protoporphyrin IX monomethyl ester (oxidative) cyclase, the system responsible for the formation of the chlorophyll isocyclic ring in developing cucumber (Cucumis sativus L. cv Beit Alpha) chloroplasts, was resolved into two enzymic components: a high-speed supernatant and a membrane pellet. This reconstituted enzyme system required reduced pyridine nucleotide for activity.

II Teile dieser Arbeit basieren auf Veröffentlichungen, die aus der Zusammenar-beit mit anderen Wissenschaftlerinnen und Wissenschaftlern entstanden sind. Zu allen diesen Inhalten wurden wesentliche Beiträge geleistet. Baumträger haben und ein Algorithmus, um einen solchen effizient zu berechnen, falls er existiert.

Photosynthetic pigments from etiolated cucumber (Cucumis sativus var. Beit Alpha improved, Hazera Co., Gedera) cotyledons were extracted by direct immersion of the intact cotyledons into the solvent N,N-dimethylformamide (DMF). The solvent is especially efficient when pigment concentration is low; time and tools are saved and the loss of pigment that usually occurs in more complicated extractio...

1. Department of Surgery, College of Medicine, University of Malawi, Blantyre, Malawi 2. Beit CURE International Hospital, Blantyre, Malawi 3. Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, United Kingdom 4. Centre for Global Surgery, McGill University Health Centre, Montreal, Quebec, Canada 5. Nuffield Department of Orthopaedics, Rheumatology and Musculo...

Contagious sterility in the parasitoid wasp Eretmocerus mundus (Hymenoptera: Aphelinidae) Elad Chiel a , Dan Gerling b , Shimon Steinberg c , Johannette Klapwijk d , Karel Bolckmans d & Einat Zchori-Fein a a Department of Entomology, Newe-Ya'ar Research Center, RamatYishay, 30095, ARO, Israel b Department of Zoology, Tel Aviv University, Ramat Aviv, 69978, Israel c Bio-Bee Biological Systems, K...

High pressure liquid chromatography was used to demonstrate that chelation of Mg(2+) into protoporphyrin IX precedes methylation in isolated greening etioplasts from cucumber (Cucumis sativus L. var. Beit Alpha) cotyledons. Mg-protoporphyrin IX synthesized in vitro from protoporphyrin IX, Mg(2+), and ATP or exogenous Mg-protoporphyrin IX could serve as substrates for the methylation step. In ei...

Detached cucumber (Cucumis sativus L. var. Beit Alpha) cotyledons incubated in darkness with 5-aminolaevulinic acid and either 16O2 air (control) or 18O2 in N2 accumulated protochlorophyllide. This was converted into methyl phaeoporphyrin alpha 5 and analysed by mass spectrometry. The molecular ion of the methyl phaeoporphyrin alpha 5 derived from the 18O2 incubation was 2 mass units greater th...