Albumin (Latin: albus, white) refers generally to any
proteinwith water solubility, which is moderately soluble in concentrated salt solutions, and experiences heat coagulation (protein denaturation). Substances containing albumin, such as egg white, are called "albuminoids".
The most well-known type of albumin is the
serum albuminin the blood.
Serum albumin is the most abundant
blood plasmaprotein and is produced in the liverand forms a large proportion of all plasma protein. The human version is human serum albumin, and it normally constitutes about 70% of humanplasma protein; all other proteins present in blood plasma are referred to collectively as globulins.
Serum albumins are important in regulating blood volume by maintaining the
osmotic pressureof the blood compartment. They also serve as carriers for molecules of low water solubility, including lipid soluble hormones, bilesalts, bilirubin, free fatty acids ( apoprotein), calcium, iron ( transferrin), and some drugs. Competition between drugs for albumin binding sites may cause drug interaction by increasing the free fraction of one of the drugs, thereby affecting potency.
Specific types include:
human serum albumin
bovine serum albumin(cattle serum albumin) or BSA, often used in medical and molecular biology labs.
Low albumin (hypoalbuminaemia) may be caused by liver disease,
nephrotic syndrome, burns, protein-losing enteropathy, malabsorption, malnutrition, late pregnancy, artefact, posture, genetic variations and malignancy.
High albumin is almost always caused by dehydration. In some cases of retinol (Vitamin A) deficiency the albumin level can become raised to borderline High-normal values. This is because retinol causes cells to swell with water (this is also the reason too much Vitamin A is toxic)
Normal range of human serum albumin in adults (> 3 y.o.) is 3.5 to 5 g/dL. For children less than three years of age, the normal range is broader, 2.5-5.5 g/dL. ["Normal Ranges for Common Laboratory Tests." Rush University. [http://www.rush.edu/webapps/rml/RMLRangesCMP.jsp] ]
Other types include the
storage protein ovalbuminin egg white, and different storage albumins in the seeds of some plants. Note that albumin is spelled with an "i" while "albumen" with an "e" is the white of an egg.
* [http://www.albumin.org/ The Albumin website ]
Cohn process(human serum albumin purification method)
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