Unusual stability properties of a reptilian ceruloplasmin.
Ceruloplasmin from the turtle Caretta caretta was isolated to purity by using the single-step procedure recently developed by us to purify sheep and chicken ceruloplasmin. It has a Mr of ca. 145,000 and a total copper content of 5.1 +/- 0.2 atoms of copper per molecule, 50% of which are detectable by EPR. The spectroscopic features include an absorption maximum at 603 nm in the electronic spectrum and the total absence of any resonance attributable to Type 2 copper in the EPR spectrum. Turtle ceruloplasmin was found to be unusually resistant to aging and proteolysis, when compared to ceruloplasmins isolated from other species. p-Phenyl-endiamine oxidase activity measurements revealed an unusually low catalytic efficiency, while the kinetic parameters of Fe(II) oxidation were consistent with those reported for other species of ceruloplasmin.
Musci
G
G
Center of Molecular Biology of C.N.R., University of Rome, La Sapienza, Italy.
Carbonaro
M
M
Adriani
A
A
Lania
A
A
Galtieri
A
A
Calabrese
L
L
D000818:Animals; D002570:Ceruloplasmin / Q000302:isolation & purification*; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D012756:Sheep; D014426:Turtles / Q000502:physiology*
D002570:Ceruloplasmin