title: [Metabolism and action of intracellular magnesium (author's transl)].
abstract: The activity of Mg2+-activated enzymes shows a bell shaped pMg dependency, with a pMg optimum at 3. Intracellular Mg2+ concentrations, determined by different methods, are about 10(-3) mol/1. Thus Mg2+-dependent enzymes are optimally activated, or nearly so, with Mg2+. If the substrates of an enzyme form complexes with Mg2+ of different stabilities, and if free substrate and the substrate-Mg2+ complex react differently with the enzyme, the equilibrium will change with the concentration of Mg2+. When the extracellular concentration of Mg2+ is increased, Mg2+ becomes bound practically exclusively to the cell membrane. In Mg2+ deficiency, the intracellular concentrations of Na+, K+, Ca2+ and cycl. AMP are changed, and the rates of synthesis of DNA, RNA and protein are decreased.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004273:DNA, Neoplasm / Q000096:biosynthesis; D004789:Enzyme Activation / Q000187:drug effects; D004798:Enzymes / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D006666:History of Medicine; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism* / Q000494:pharmacology; D009363:Neoplasm Proteins / Q000096:biosynthesis; D011188:Potassium / Q000378:metabolism; D012334:RNA, Neoplasm / Q000096:biosynthesis; D012517:Sarcoma, Yoshida / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D004273:DNA, Neoplasm; D004798:Enzymes; D009363:Neoplasm Proteins; D012334:RNA, Neoplasm; D012964:Sodium; D000242:Cyclic AMP; D008274:Magnesium; D011188:Potassium; D002118:Calcium
vernacular_title: Stoffwechsel und Wirkungen des intrazellulären Magnesium.