Carbamoyl phosphate biosynthesis and partition in pyrimidine and arginine pathways of Escherichia coli. In situ properties of carbamoyl-phosphate synthase, ornithine transcarbamylase and aspartate transcarbamylase in permeabilized cells.

A procedure for the permeabilization of Escherichia coli cells was adapted to the in situ determination of the catalytic and regulatory properties of the enzymes responsible for the biosynthesis of carbamoyl phosphate and its utilization in the pyrimidine and arginine pathways. Differences in enzyme sensitivity to effectors and changes in pH dependence were observed. Partition of carbamoyl phosphate in the two metabolic pathways could be measured under conditions of substrate saturation. The results obtained will allow to test experimentally the theoretical predictions made by A. Goldbeter (1973) PhD thesis, Université Libre de Bruxelles, on the distribution of carbamoyl phosphate and the oscillation of its intracellular concentration.