Assay for the enzymatic conversion of indoleacetic acid to 3-methylindole in a ruminal Lactobacillus species
| Autor: | James R. Carlson, D. C. Honeyfield |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1990 |
| Předmět: |
Indoles
Rumen Dithionite Aminopterin Applied Microbiology and Biotechnology chemistry.chemical_compound Non-competitive inhibition medicine Animals chemistry.chemical_classification Ecology biology Indoleacetic Acids Proteolytic enzymes Substrate (chemistry) food and beverages Enzyme assay Enzymes Skatole Kinetics Lactobacillus Enzyme Biochemistry chemistry biology.protein Cattle Food Science Biotechnology medicine.drug Research Article |
| Popis: | An assay to measure the rate of enzymatic formation of 3-methylindole (3MI) from indoleacetic acid (IAA) in Lactobacillus sp. strain 11201 was developed. The reaction mixture contained 50 micrograms of microbial protein per ml (range, 25 to 100 mg/ml), essential low-molecular-weight reaction ingredients, and radiolabeled IAA as substrate (range, 0 to 2 mM IAA). The reaction was anaerobic for 25 min at 39 degrees C. The apparent Michaelis-Menten constants were: Km, 0.14 mM IAA; and Vmax, 64 nmol 3MI.mg-1.min-1. The inhibitors avidin, aminopterin, and EDTA had no effect on the 3MI-forming enzyme. Dithionite stimulated the 3MI-forming enzyme. The product of the reaction, 3MI, acted as a noncompetitive inhibitor of the enzyme. Enzyme activity was associated with the cell wall fraction after sonication; treatment with the French press; or treatment with detergents, proteolytic enzymes, and EDTA. |
| Databáze: | OpenAIRE |
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