Distribution of Steroid 1-Dehydrogenation and Side-Chain Degradation Enzymes in the Spores of Fusarium solani : Causes of Metabolic Lag and Carbohydrate Independence
| Autor: | Rosaire Plourde, Hamdallah Hafez-Zedan |
|---|---|
| Rok vydání: | 1973 |
| Předmět: |
Spores
Nystatin Time Factors General Biochemistry Genetics and Molecular Biology Acetone Cell wall Cell membrane chemistry.chemical_compound Enzyme activator Fusarium Cell Wall Benzene Derivatives Hydroxyprogesterones medicine General Pharmacology Toxicology and Pharmaceutics Biotransformation Metabolism and Products chemistry.chemical_classification General Immunology and Microbiology fungi Cell Membrane General Medicine Periplasmic space Metabolism Hydrogen-Ion Concentration Spores Fungal Spore medicine.anatomical_structure Enzyme chemistry Biochemistry Alcohols Phenethyl alcohol Androstenes Chloroform Hydrochloric Acid Oxidoreductases |
| Zdroj: | Applied Microbiology. 25:650-658 |
| ISSN: | 0003-6919 |
| DOI: | 10.1128/am.25.4.650-658.1973 |
| Popis: | The spores of a strain of Fusarium solani 1-dehydrogenate ring A and cleave the 17β-acetyl side chain of 17α-hydroxypregn-4-ene-3,20-dione (17α-hydroxyprogesterone) to give 17α-hydroxypregna-1,4-diene-3,20-dione (the 1-dehydro analogue) and little androsta-1,4-diene-3,4-diene-3,17-dione (androstadienedione). A 4-h lag period is observed in the course of metabolism, and there are no requirements for external additives. Exoenzymes or surface enzymes bound to the cell outside the plasma membrane, either in the periplasmic space or bound to the cell wall, cannot be detected. The spore activity is not destroyed by treatment with aqueous HCl (pH 1.50), indicating that the 1-dehydrogenation and side-chain degradation enzymes are located away from the surface of the spores. Phenethyl alcohol destroys the spore permeability barriers, and it is also likely that it exposes its enzymes to acid inactivation. The action of phenethyl alcohol is reversible at low concentrations and irreversible at high concentrations. This investigation shows that: (i) the spore 1-dehydrogenating and side-chain-degrading enzymes appear to be bound to, or imbedded in, the plasma membrane; (ii) the lag period observed in the course of metabolism of the steroid by the spores might be required for enzyme activation or diffusion of the substrate through the cell wall; and (iii) the internal metabolities of the spores, that might be required for the conversion process, appear to be present in a nondiffusible form or bound to intrasporal macromolecules. |
| Databáze: | OpenAIRE |
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