✍ Scribed by H�ttermann, A. ;Porter, M. T. ;Rusch, H. P.
No coin nor oath required. For personal study only.
The activities of seven enzymes were studied during the first 24 h of spherule formation (differentiation) in cultures of Physarum polycephaIum. These enzymes were: isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase, glutamate dehydrogenase, acid phosphatase, phosphodiesterase, fl-glucosidase, and histidase. Isocitrate dehydrogenase and glucose-6-phosphate dehydrogenase showed a decrease, glutamate dehydrogenase and phosphodicsterase increased about eight-fold, acid phosphatase about two-fold,/?-glucosidase showed an activity peak at about 15 h after starvation which decreased after 24 h to its original value, and histidase showed no significant activity change during the period. The inhibition of protein synthesis by cycloheximide resulted in a decrease of enzymic activity at all times during the process, whereas the inhibition of RNA synthesis by actinomycin D had no effect during the early stages of spherulation but resulted in a rather rapid decrease of enzymic activity when added 21 h after the initiation of spherule formation. Attempts to induce higher enzymic activities during spherulation above the levels already observed were unsuccessful.
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## Abstract The rate of NAD turnover in microplasmodia of __Physarum polycephalum__ was investigated using a double labeling technique with (^14^C)‐adenine or adenosine and (^3^H)‐nicotinamide. The half‐life of an NAD molecule in __Physarum__ was estimated to be 25 min, which is shorter than in ei
## Abstract Homogenates of __Physarum polycephalum__ incorporate [^3^H] dATP into nuclear DNA at an initial rate of approximately 15% of the in vivo rate. To attain this level of synthesis, cultures are homogenized in a medium containing Mg^++^, EGTA, glucose and spermine. Incorporation is strongly