Effect of anaerobiosis and glucose on the content of haem and its precursors in intact yeast cells

• Published in: Acta biochimica polonica Vol. 26; no. 1-2; pp. 161 - 169
• Main Authors: Lukaszkiewicz, J, Biliński, T
• Format: Journal Article
• Language: English
• Published: Poland 1979
• Subjects: 5-Aminolevulinate Synthetase - metabolism; Aminolevulinic Acid; Anaerobiosis; Culture Media; Glucose - pharmacology; Heme - biosynthesis; Porphobilinogen Synthase - metabolism; Yeasts - cytology; Yeasts - growth & development; Yeasts - metabolism
• ISSN: 0001-527X

The content of haem and its precursors was determined in yeast cells grown under various conditions. The cells grown aerobically on 2% galactose contain about three times more haem (about 300 nmoles/g dry wt.) than the cells grown on 10% glucose. A trace amount of haem was found in anoxia irrespective of the carbon source used. The "efficiency" of the first enzyme of the haem biosynthetic pathway--delta-aminolevulinic acid (ALA) synthetase--expressed as the sum of all intermediates of the pathway in the cells grown on galactose, is similar in anaerobic and aerobic cells. The "efficiency" of the second enzyme--ALA dehydratase--is lower about three times both in anoxia and under conditions of glucose repression. In anoxia, not haem but delta-aminolevulinic acid is the main biosynthetic product. The role of glucose repression and of the feedback mechanisms in regulation of haem synthesis in yeast is discussed. A method for haem determination in the intact yeast cells, based on the formation of pyridine haemochrome, is described.