The cellular oxygen supply in the isolated, hemoglobin-free perfused, working rat heart can be determined by measurements of myoglobin oxygenation. However, for a precise analysis of mitochondrial hypoxia and anoxia (pO2 < 0.01 Torr) redox-state of respiratory enzymes must be known. By use of the EMPHO (Frank et al. 1989) it is possible to perform a high speed spectrometry within very small tis...

A new idea that elucidates the electron carrier ability of plastocyanin (and o f azurin) is proposed. It emphasizes the fact that two lobes of the d-orbital. where one unpaired electron of copper (II) ion lies, are not screened by the ligand atoms, which would facilitate the electron transfer between the d-orbital and the redox partners (cytochrom e/ and P-700 in the case of plastocyanin). Seve...

Nitrate reductase from mutant 305 o f Chlamydomonas reinhardii has been purified about 90-fold and biochemically characterized. The enzyme can use reduced flavins and viologens as electron donors to reduce nitrate but, unlike the nitrate reductase com plex from its parental wild strain, lacks NAD(P)H-nitrate reductase and NAD(P)H-cytochrom e c reductase activities, does not bind to Blue-Agarose...