| Popis: |
Labelled ferritin from HeLa cells growing in suspension has been extracted. A qualitative study of the kinetics of labelling has shown that: 1. 1. The iron begins to be incorporated without any lag phase. The activity increases linearly with time and finally reaches a constant level. The time needed for that level to be attained, the speed of labelling, and the level of the saturation plateau all vary inversely with the concentration of added iron. 2. 2. The activity peaks located at 94 S, 65 S and 8 S correspond respectively to ferritin in dimer and monomer forms and to a material of unknown origin. 3. 3. Experiments with actinomycin D and cycloheximide all lend support to the presence of a certain basal level of ferritin in HeLa cells. That level may be reduced and ferritin molecules may even totally disappear according to the physiological state of the cells. |
