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The interaction of Ca 2+ ‐binding proteins with the carbocyanine dye stains‐all
Author(s) -
Caday Cornelio G.,
Lambooy Peter K.,
Steiner Robert F.
Publication year - 1986
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360250814
Subject(s) - parvalbumin , chemistry , calmodulin , troponin c , absorption band , mole , absorption (acoustics) , analytical chemistry (journal) , biophysics , crystallography , troponin , calcium , chromatography , biochemistry , organic chemistry , optics , psychology , physics , neuroscience , psychiatry , myocardial infarction , biology
The interaction of the carbocyanine dye Stains‐all with the Ca 2+ ‐binding proteins calmodulin, troponin C, and parvalbumin has been monitored by means of absorption spectra and CD. In the absence of Ca 2+ , complexes with Stains‐all of all three proteins exhibit at high dye: protein mole ratios an intense J absorption band at 600–650 nm, which is associated with a characteristic CD spectrum. In the cases of calmodulin and troponin C, the J‐band is progressively lost as the dye: protein ratio decreases and is replaced by bands of the γ and β types at 450–550 nm, which likewise give rise to characteristic CD spectra. For parvalbumin, only the J‐band is observed; its intensity is undiminished at the lowest dye: protein ratios examined. In the presence of excess Ca 2+ the J‐band is lost for all three proteins. For calmodulin and troponin C it is replaced by σ‐ and β‐bands; in the case of parvalbumin the bound dye is released. A tentative model has been proposed to account for these observations.