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.
|Titolo:||Metal Ion Binding to Parvalbumin : A Proton NMR Study|
RAGG, ENZIO MARIA (Primo)
|Parole Chiave:||parvalbumin ; NMR ; ion binding|
|Settore Scientifico Disciplinare:||Settore CHIM/06 - Chimica Organica|
|Data di pubblicazione:||1986|
|Digital Object Identifier (DOI):||10.3891/acta.chem.scand.40b-0006|
|Appare nelle tipologie:||01 - Articolo su periodico|