Purification and characterization of eucaryotic alanine racemase acting as key enzyme in cyclosporin biosynthesis
| Autor: | Rainer Zocher, Horst Kleinkauf, E Schneider-Scherzer, Kai Hoffmann |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Stereochemistry
Biology Biochemistry Piperazines chemistry.chemical_compound Multienzyme Complexes Cyclosporin a Alanine racemase Arginine racemase Peptide Synthases Pyridoxal phosphate Molecular Biology Alanine Gel electrophoresis chemistry.chemical_classification Molecular mass Alanine Racemase Cell Biology Enzyme chemistry Chromatography Gel Cyclosporine Electrophoresis Polyacrylamide Gel Chromatography Thin Layer Mitosporic Fungi |
| Zdroj: | Journal of Biological Chemistry. 269:12710-12714 |
| ISSN: | 0021-9258 |
| Popis: | A specific alanine racemase, which is a key enzyme in the biosynthesis of the undecapeptide cyclosporin A, was purified to electrophoretic homogeneity from the fungus Tolypocladium niveum. This is the first enzyme of this kind isolated from a eucaryotic organism. The enzyme catalyzes the reversible racemization of alanine and requires pyridoxal phosphate as the exclusive cofactor. Km values for L- and D-alanine were found to be 38 and 2 mM, respectively. Maximal reaction velocity was observed at 42 degrees C and pH 8.8 for the L to D direction. Molecular mass determinations of the denatured enzyme by SDS-polyacrylamide gel electrophoresis gave a value of 37 kDa, whereas gel filtration calibration studies yielded a value between 120 and 150 kDa, indicating an oligomeric native structure. |
| Databáze: | OpenAIRE |
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