ISSN:
1432-2048
Keywords:
Key words: Anthraquinone biosynthesis
;
Galium
;
Isochorismate hydroxymutase
;
Rubiaceae
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract. Isochorismate hydroxymutase (i.e. isochorismate synthase, EC 5.4.99.6) was purified from an anthraquinone-producing cell-suspension culture of Galium mollugo L. Although attempts to stabilize the labile enzyme met with little success, a substantial increase in enzyme activity was observed in the presence of glycine betaine (500 mM). Column chromatography on solid supports other than diethylaminoethyl (DEAE)-Sephacel, Phenylsepharose Cl-4B or Cibacron Blue 3G-A did not give active enzyme preparations. In spite of these drawbacks the enzyme was purified 573-fold. Enzyme activity depended strictly on the presence of Mg2+. Kinetic data for chorismate in the forward reaction (K m = 807 μM, V max = 6.2 pkat · mg−1) and for isochorismate in the reverse reaction (K m = 675 μM, V max = 5.9 pkat · mg−1) were determined.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004250050120
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