title: Magnesium-dependent conformational changes of membrane proteins are related to the Mg2+-dependent ATPase activity in cardiac sarcolemma.
abstract: Magnesium-induced enzymatic and structural changes of membrane-bound proteins in rat heart sarcolemma have been investigated. In the absence of ATP, increasing concentrations of magnesium within the range 0.1-10.0 mM gradually lowered the alpha-helix content of sarcolemmal proteins. The same magnesium concentrations stepwise activated the Mg2+-dependent ATPase in the presence of ATP. Mathematical and graphical analysis of the data yielded a quantitative relationship between magnesium-induced stimulation of the Mg2+-dependent ATPase activity and diminution of the alpha-helix content of membrane proteins in cardiac sarcolemma.
authors.forename: N
authors.initials: N
authors.lastname: Vrbjar
authors.forename: J
authors.initials: J
authors.lastname: Soos
authors.forename: A
authors.initials: A
authors.lastname: Ziegelhöffer
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase; D055598:Chemical Phenomena; D002621:Chemistry; D008274:Magnesium / Q000502:physiology*; D008297:Male; D008433:Mathematics; D008565:Membrane Proteins / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology*; D011487:Protein Conformation; D051381:Rats; D011919:Rats, Inbred Strains; D012508:Sarcolemma / Q000201:enzymology*
chemical_list: D008565:Membrane Proteins; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D008274:Magnesium