Regulation of Phenylalanine and Tyrosine
... NaCI, 5 ; MgS0,.7H,O, 0.5; pH 7.0. Cells for the preparation of enzymes were harvested in the lateexponential phase of growth by centrifugation. The yield was approximately 2.5 g wet weight cells per litre
medium. The cells were stored at - 18 "C.
Enzyme assays. Buffer A (50 mM-Tris/HCI, pH 7-7, con ...