The multidomain structure of ceruloplasmin from calorimetric and limited proteolysis studies.

摘要: Differential scanning calorimetry has been used to investigate the thermal stability of three different ceruloplasmins (from sheep, chicken, and turtle) in their native state after limited proteolysis. The undegraded proteins showed a similar structural organization calorimetric domains, although temperature unfolding varied from 57.8 degrees C (turtle) 71.2 (sheep) 82.1 (chicken). spectroscopic catalytic properties were totally lost at temperatures corresponding less thermostable domain case sheep chicken most turtle protein. Trypsin, but not plasmin, digestion caused significant decrease ceruloplasmins. Turtle ceruloplasmin was insensitive both proteases. Comparing thermodynamic parameters protein its cleaved states revealed mismatch between domains 3-fold internal replication primary structure, which is evident highly homologous, fully sequenced human Copper removal rearrangement molecule only two suggesting role metal atoms organizing new domain, tentatively assigned cooperative unit