The effect of glutamine concentration on the activity of carbamoyl-phosphate synthase II and on the incorporation of [3H]thymidine into DNA in rat mesenteric lymphocytes stimulated by phytohaemagglutinin.

摘要: The maximum catalytic activities of carbamoyl-phosphate synthase II, a limiting enzyme for pyrimidine nucleotide synthesis, are very much less than those glutaminase, glutamine utilization, in lymphocytes and macrophages; the flux through pathway formation de novo is only about 0.4% rate utilization by lymphocytes. Km II 16 microM concentration necessary to stimulate lymphocyte proliferation half-maximally 21 microM. This agreement suggests that importance these cells provision nitrogen biosynthesis nucleotides (and probably purine nucleotides). However, half-maximal stimulation (glutaminolysis) 2.5 mM. fact markedly excess synthesis ‘half-maximal concentration’ values so different, glutaminolytic independent use synthesis.