Caeruloplasmin is a protein found in blood plasma. It is a ferroxidase, an enzyme that plays an important role in the storage of copper. The determination of caeruloplasmin provides information about iron and also copper metabolism.
What is caeruloplasmin?
Caeruloplasmin is also known as ceruloplasmin. It is the protein that is mainly responsible for copper transport in the blood. In addition, caeruloplasmin is an essential component of iron metabolism. It belongs to the group of copper-dependent ferroxidase. Caeruloplasmin has homologies, similarities with the protein hephaestin. This protein is also important for iron metabolism. Hephaestein is a transmembrane copper-binding ferroxidase. It transports iron from enterocytes in the intestine, which absorb iron from food, to the bloodstream.
Function, effects, and roles in body and health
Caeruloplasmin binds over 95% of the copper in human serum. It is also an essential component of iron metabolism. It oxidizes iron, which is bound to ferritin. Fe3+ is formed from Fe2+. An oxidation is a chemical reaction in which an atom loses electrons, thereby increasing its positive charge. When another atom accepts these surrendered electrons, it is called a redox reaction because one atom is reduced and another atom is oxidized. Caeruloplasmin is used to transport copper with the help of transferrin. Transferrin is a glycoprotein that can only bind and transport Fe3+. Iron is an important component of the protein hemoglobin and myoglobin. Hemoglobin is an iron-containing protein of red blood cells and gives them their red coloration. It is used to transport oxygen in the blood. Myoglobin is a protein in the muscles. It is also a red protein that binds oxygen in the muscle along with other enzymes, the hydrogenases and the oxidases. In addition, iron is involved in electron transport in mitochondria, the power plants of the cell.
Formation, occurrence, properties, and optimal levels
Caeruloplasmin has a molecular mass of 151 kDa. It is produced mainly in the liver and brain. The synthesis of caeruloplasmin is not affected by an altered occurrence of copper. After synthesis, each protein is loaded with six to eight copper ions. Men and women have an average caeruloplasmin concentration of 20 to 60 mg/dl. The amount of copper in the human body is about 70 to 150 mg. The concentration of iron ranges from 60 to 160 µg/dl in men and 40 to 150 µg/dl in women.
Diseases and disorders
The concentration of caeruloplasmin in the blood can be altered by various diseases or life circumstances. These circumstances include prolonged malnutrition. Chronic deficiency of copper occurs, which, in contrast to short-term deficiency of copper, can affect the concentration of caeruloplasmin. Another reason may be decreased expression of the gene encoding caeruloplasmin. A disease associated with decreased levels of caeruloplasmin is Menkes syndrome. This disease is a congenital metabolic disorder. Movement disorders occur due to muscle weakness. The connective tissue loses its elasticity. This is also called seborrheic dermatitis. The hair loses its structure and becomes brittle. In some cases, a funnel chest may form. There is also an increased incidence of hernias. The cause of this disease is the disturbed transport of copper through the intestine. Another disease in which there is a decreased amount of caeruloplasmin is Wilson’s syndrome. Like Menkes syndrome, this is a genetic disorder. In this disease, there is a ϋexcessive accumulation of copper, which has serious consequences for the liver and brain. Therefore, there are limitations in the functions of the brain and liver. It can lead to acute failure of the liver. Patients may also experience neurological symptoms. After the onset of Wilson’s syndrome, symptoms similar to those of Parkinson’s patients may occur. These include slowed movements, loss of balance, tremor of the hand, or ataxia. Ataxia is generally a disorder of movement.Different forms of ataxia are distinguished; runpfataxia, gait ataxia and stance ataxia. In addition, caeruloplasmin deficiency can occur due to vitamin C overdose or acaeruloplasminemia. In acaeruloplasminemia, a mutation causes a dysfunction in the ability of caeruloplasmin to function as a ferroxidase. It is no longer able to oxidize iron. An accumulation of iron in the human body occurs. Accumulation of Fe2+ in high doses is toxic to humans. This accumulation occurs mainly in the liver, pancreas as well as in the brain. The result is diseases such as diabetes mellitus, degeneration of the retina, and neurological impairments such as dementia or ataxia. An increase in the amount of caeruloplasmin can be triggered by pregnancy, taking the birth control pill, Alzheimer’s disease or schizophrenia. Other causes of increased caeruloplasmin levels include rheumatoid arthritis and angina. Arthritis is an inflammation of the joints. Angina refers to a variety of conditions. Among them is the best known angina, which mainly causes chest pain.
