intensity of fluorescence induced by reaction of a sh-directed fluorogenic reagent with whole chang liver cells or their plasma membrane preparations which were previously treated with 0.5 mm n-ethylmaleimide ( nem ) plus 5 mm leucine was enhanced by 30 % or more in the presence of 5 mm leucine or valine in assay medium consisting of tris-hepes buffer , ph 6.85 , compared with the control .
C0007634
cells
C0007603
plasma membrane