Calreticulin is a thermostable protein with distinct structural responses to different divalent cation environments.

ABSTRACT: Calreticulin is a soluble calcium-binding chaperone of the endoplasmic reticulum (ER) that is also detected on the cell surface and in the cytosol. Calreticulin contains a single high affinity calcium-binding site within a globular domain and multiple low affinity sites within a C-terminal acidic region. We show that the secondary structure of calreticulin is remarkably thermostable at a given calcium concentration. Rather than corresponding to complete unfolding events, heat-induced structural transitions observed for calreticulin relate to tertiary structural changes that expose hydrophobic residues and reduce protein rigidity. The thermostability and the overall secondary structure content of calreticulin are impacted by the divalent cation environment, with the ER range of calcium conc

SUBMITTER: Wijeyesakere SJ 

PROVIDER: S-EPMC3058961 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature