Caeruloplasmin: A Plasma Protein, Enzyme, and Antioxidant

Abstract

Multifunctional roles of the plasma protein, caeruloplasmin, have been briefly reviewed under three main headings. These are protein functions, enzymic activity, and antioxidant protection. As a plasma protein it is said to play a role in the transport of copper. Since some 95 % of serum copper is associated with caeruloplasmin, measurement of the protein provides a useful guide to copper levels. Enzymic functions are related to its oxidase activity. Substrates commonly used for laboratory assay include non-biologically occurring aromatic amines and polyphenols. More recently, a physiological function has been proposed in which the enzyme oxidases iron from the ferrous to ferric state for binding to apotransferrin. This enzymic function of caeruloplasmin has been designated ‘ferroxidase’. In vitro studies have shown that caeruloplasmin can inhibit the peroxidation of polyunsaturated fatty-acids. This function is in part related to its ferroxidase activity. No antioxidant activity has yet been demonstrated in vivo but this possibility is speculatively discussed.

Evaluation of Oxidative Stress during Toxoplasmosis in Pregnant Women

“…[30] In the present study, CP concentration was lower in T. gondii seropositive pregnant women (P<0.05).It acts as an antioxidant through either prevention of decompartmentized iron acting as free radical catalysis or by directly inactivating the free radical and CP was far more effective as a peroxyl radical scavenger than SOD, deferoxamine and BSA, but slightly less effective than catalase. [31] This result agreed with other researches. [32] In positive toxoplasmosis group, the result of uric acid was significantly increased.…”

Ceruloplasmin Protects Injured Spinal Cord from Iron-Mediated Oxidative Damage

“…Cp is an acute phase reactant, whose concentration in serum increases with systemic inflammation (Vassiliev et al, 2005). Its properties as an antioxidant are well established, and it is thought to account for most of the antioxidant properties of serum (Gutteridge, 1978;Vassiliev et al, 2005). In the CNS, however, a GPI-anchored variant is the major form of the protein and is expressed by astrocytes (Patel et al, 2000).…”

Evaluation of Oxidative Stress in Type 2 Diabetes Mellitus Patients

“…Ceruloplasmin acting as ferroxidase decreases the availability of the iron in free radical generating reactions [5]. Considering the pro-oxidant status of patients with T2DM, an increase in the level of CP probably favours its protective action against free radical injury [6].…”