ISSN:
0138-4988
Keywords:
Life Sciences
;
Life Sciences (general)
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Two isoenzymes of chorismate mutase (EC 5.4.99.5), designated as CM-1 and CM-2, were isolated and partially purified from suspension-cultured cells of Ruta gravelens by DEAE-sephacel chromatography and gel filtration. 60-72% of the total activity measured after DEAE-sephacel chromatography were obtained as CM-1 and 28-40% were CM-2 activity. CM-1 was inhibited by phenylalanine (K1 = 4 · 10-6 M) and tyrosine (K1 = 8. 10-6M) and activated by tryptophan. In contrast, CM-2 was not influenced by these three amino acids. The molecular weights estimated by gel filtration on SEPHADEX G-150 were 56000 for CM-1 and 45000 for CM-2, respectively. Both isoenzymes were stable at -20°C, but exhibited different behaviour during thermal inactivation and different optima of reaction temperature. CM-1 catalysed the reaction at a pH optimum of pH 7.8 and CM-2 showed a broad optimum between 6-10. The Km-values for chorismic acid were determined to be 1.1 mM for CM-1 and 0.5 mM for CM-2. The isoenzymes showed different behaviour to inhibitors of sulfhydryl groups. There were no differences in all parameters of chorismate mutase examined for two various cell lines of Ruta graveolens.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/abio.370110113
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