Metal ion binding to parvalbumin. A proton NMR study.
The 1H NMR spectra of carp parvalbumin saturated with Ca2+, Cd2+, La3+ and Lu3+ were compared, using 2D 1H NMR techniques as well as conventional 1H NMR spectra. The Ca2+ and Cd2+ saturated parvalbumin (with both high affinity Ca2+-binding sites occupied) gave rise to very similar spectra. This shows that these two species have almost identical protein conformations. The 1H NMR spectrum from the Ln3+ saturated parvalbumins deviated from the other two and it was therefore concluded that Cd2+ is a better probe for Ca2+ than Ln3+ in parvalbumin and probably also for related calcium binding proteins. The addition of excess of divalent metal ions, such as Mg2+ or Ca2+, causes small changes in the chemical shift of some methyl resonances. This is presumably caused by binding of these metal ions to a third site close to the CD site which is made up of the carboxylic groups from Glu 60 and Asp 61.
D000818:Animals; D002104:Cadmium / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002347:Carps; D007811:Lanthanum / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000378:metabolism*; D009124:Muscle Proteins / Q000378:metabolism*; D010320:Parvalbumins / Q000378:metabolism*; D011485:Protein Binding
D008670:Metals; D009124:Muscle Proteins; D010320:Parvalbumins; D002104:Cadmium; D007811:Lanthanum; D002118:Calcium