Glutam ine synthetase was partly purified from Chlorella pyrenoidosa. This enzyme activity was stimulated by dithioerythritol and 2'-3'-dimercaptopropanol (BAL). Full activation was obtained by thioredoxins isolated from the cyanobacterium Synechococcus 6301, from spinach and by heated Chlorella extract. The apparent Km for the purified thioredoxin B from Synechococcus 6301 was determined to be...

Thioredoxins are small globular proteins that proved to be excellent model for investigating the relationship between the structure of protein and their physico-chemical and functional properties. The results from the experiments on thioredoxins offer the basic for the development of the new paradigms in the field of chemistry, biophysics and biology of proteins, with special attention to redox...

Proviral factors are host proteins hijacked by viruses for processes essential for virus propagation such as cellular entry and replication. Pathogens and their hosts co-evolve. It follows that replacing a proviral factor with a functional ancestral form of the same protein could prevent viral propagation without fatally compromising organismal fitness. Here, we provide proof of concept of this...

A role for thioredoxin in metazoan DNA synthesis has been assessed by injecting rapidly dividing Xenopus eggs with purified heterologous thioredoxins, which might act as inhibitors if they were to replace resident thioredoxins in some but not all reaction steps. Of 10 tested proteins, spinach chloroplast thioredoxin m is the most potent inhibitor. Eggs cleave and produce cells lacking nuclei. D...

Our studies in yeast show that there is an essential requirement for either an active thioredoxin or an active glutathione (GSH)-glutaredoxin system for cell viability. Glutathione reductase (Glr1) and thioredoxin reductase (Trr1) are key regulatory enzymes that determine the redox state of the GSH-glutaredoxin and thioredoxin systems, respectively. Here we show that Trr1 is required during nor...

Petra Langlotz, Wolfgang Wagner, and Hartmut Follmann Fachbereich Chemie der Philipps-Universität, Biochemie, Hans-Meerwein-Straße. D-3550 Marburg, Bundesrepublik Deutschland Z. Naturforsch. 41c, 979—987 (1986); received August 1/September 19, 1986 Am ino Acid Composition, A lgae, Ribonucleotide Reductase, Scenedesmus obliquus, Thio­ redoxin A comprehensive thioredoxin profile of Scenedesmus ob...

Cyanobacteria perform oxygenic photosynthesis, which gives rise to the continuous production of reactive oxygen species, such as superoxide anion radicals and hydrogen peroxide, particularly under unfavorable growth conditions. Peroxiredoxins, which are present in both chloroplasts and cyanobacteria, constitute a class of thiol-dependent peroxidases capable of reducing hydrogen peroxide as well...

Apicomplexan parasites are global killers, being the causative agents of diseases like toxoplasmosis and malaria. These parasites are known to be hypersensitive to redox imbalance, yet little is understood about the cellular roles of their various redox regulators. The apicoplast, an essential plastid organelle, is a verified apicomplexan drug target. Nuclear-encoded apicoplast proteins traffic...