title: Sodium and potassium binding to parvalbumins measured by means of intrinsic protein fluorescence.
abstract: The binding of Na+ and K+ to whiting parvalbumin (pI 4.4) and pike parvalbumins (pI 4.2 and 5.0) results in a shift of the tryptophan fluorescence spectrum towards shorter wavelengths by 2-4 nm for the whiting protein and in a rise of the tyrosine and phenylalanine fluorescence quantum yield for the pike proteins. The effective binding constants of Na+ and K+ to parvalbumins are within the range of 10 M-1 to 100 M-1. Physiological concentrations of Na+ and K+ lower the affinity of whiting parvalbumin for Ca2+ and Mg2+ by almost an order of magnitude.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D005399:Fishes; D008274:Magnesium / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism*; D010320:Parvalbumins / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D011485:Protein Binding; D012964:Sodium / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D009124:Muscle Proteins; D010320:Parvalbumins; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium