1H-NMR study of the effect of temperature through reversible unfolding on the heme pocket molecular structure and magnetic properties of aplysia limacina cyano-metmyoglobin.

ABSTRACT: Two-dimensional 1H NMR spectroscopy over a range of temperature through thermal unfolding has been applied to the low-spin, ferric cyanide complex of myoglobin from Aplysia limacina to search for intermediates in the unfolding and to characterize the effect of temperature on the magnetic properties and electronic structure of the heme iron. The observation of strictly linear behavior from 5 to 80 C degrees through the unfolding transition for all hyperfine-shifted resonances indicates the absence of significant populations of intermediate states to the cooperative unfolding with Tm approximately 80 degrees C. The magnetic anisotropies and orientation of the magnetic axes for the complete range of temperatures were also determined for the complex. The anisotropies have very similar magnitud

SUBMITTER: Xia Z 

PROVIDER: S-EPMC1366980 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature