Galactosyltransferase of Neurospora.

An enzyme, galactosyltransferase, able to catalyze the formation of galactose polymers was detected in cell-free extracts of a wild type strain of Neurospora crassa. Enzyme activity was found in both the supernatant and the particle fractions after centrifugation at 100,000 X g. The enzyme assayed in the 100,000 X g supernatant showed a 4fold difference in specific activity as compared to that found in the particle fraction.     

Photoregulation of some enzymes from Neurospora crassa

Light-grown cultures of Neurospora crassa showed photoregulation of a number of enzymes. Proteases and cytosolic malate dehydrogenase showed an increase in activity. There was a decrease in the activity of mitochondrial malate dehydrogenase, isocitrate dehydrogenase and cytosolic glucose-6P-dehydrogenase, isocitrate dehydrogenase and isocitrate lyase.     

Anticonidiogenic effect of hydroxyurea on Neurospora crassa]

Conidiation induced in a low sugar-ammonium medium (or by other means such as full starvation or heat shock) is almost fully prevented by hydroxyurea. In a parallel manner the DNA/RNA and DNA/protein ratios are prevented from increasing.     

Localization of pyruvate carboxylase in the cells of Neurospora crassa

The cell wall of Neurospora crassa was digested enzymatically and the cytosolic and the mitochondrial fractions were separated. The activity of pyruvate carboxylase (EC 6.4.1.1) was detected entirely in the cytosolic fraction. This indicates that the location of pyruvate carboxylase of N. crassa is in the cytosol, but is not in the mitochondria; this is different from the situation in animal tissues.     

GMP-stimulation of the cyanide-insensitive mitochondrial respiration in heat-shocked conidia of Neurospora crassa

In mitochondria of heat-shocked conidia of Neurospora exogenous NADH and succinate were oxidized mainly via the alternative, hydroxamate-sensitive pathway (70%) and only 30% via the cytochromic, cyanide-sensitive pathway which was predominant in untreated conidia; the alternative oxidase pathway was markedly stimulated by guanosine 5'-monophosphate (GMP).     

Change of the cytochrome oxidase level during exponential growth in Neurospora crassa.

In Neurospora cells growing in various media, the specific activity of cytochrome oxidase increases very markedly during early exponential growth, reaching a maximum after 4-5 duplication times, then it slowly declines.