Globulin

Globulin in human biochemistry is one of the three types of serum proteins, the others being albumin and fibrinogen. Some globulins are produced in the liver, while others are made by the immune system. The term globulin encompasses a heterogeneous group of proteins with typical high molecular weight, and both solubility and electrophoretic migration rates lower than for albumin. The normal concentration in blood is 2.2 to 3.9 g/dl.

It is sometimes used synonymously with globular protein. However, albumin is also a globular protein, but not a globulin. All other serum globular proteins are globulins. Protein electrophoresis is used to categorize globulins into the following four categories:

• Alpha 1 globulins
• Alpha 2 globulins
• Beta globulins
• Gamma globulins (one group of gamma globulins are immunoglobulins, that function as antibodies)

Contents 1 Plant globulins 2 Pseudoglobulins and euglobulins 3 References 4 External links

Plant globulins

Non-human globulin proteins exist as well, such as cucurbitin from squashes and vicilin and legumin from legumes and peas, functioning as protein storage within seeds. These proteins can cause allergic reactions if they bind with human IgE antibodies.^[1]

Pseudoglobulins and euglobulins

Pseudoglobulins are a fraction of globulins that are soluble in ammonium sulfate solution more so than the euglobulin fraction. Pseudoglobulins are soluble in pure water, whereas euglobulins are insoluble under the same circumstances.^[2]

References

External links

• Serum Proteins
• Cornell
• MeSH Globulins

Proteins Processes Protein biosynthesis Posttranslational modification Protein folding Protein targeting Proteome Protein methods Structures Protein structure Protein structural domains Proteasome Types List of types of proteins List of proteins Membrane protein Globular protein Globulin Albumin Fibrous protein biochemical families: prot · nucl · carb (glpr, alco, glys) · lipd (fata/i, phld, strd, gllp, eico) · amac/i · ncbs/i · ttpy/i B proteins: BY STRUCTURE: membrane, globular (en, ca, an), fibrous

Proteins: Globular proteins Serum globulins Alpha globulins serpins: alpha-1 (Alpha 1-antichymotrypsin, Alpha 1-antitrypsin) · alpha-2 (Alpha 2-antiplasmin) · Antithrombin (Heparin cofactor II) carrier proteins: alpha-1 (Transcortin) · alpha-2 (Ceruloplasmin) · Retinol binding protein other: alpha-1 (Orosomucoid) · alpha-2 (alpha-2-Macroglobulin, Haptoglobin) Beta globulins carrier proteins: Sex hormone-binding globulin · Transferrin other: Angiostatin · Hemopexin · Beta-2 microglobulin · Factor H · Plasminogen · Properdin Gamma globulin Immunoglobulins Other Fibronectin (Fetal fibronectin) · Macroglobulin/Microglobulin · Transcobalamin Other globulins Beta-lactoglobulin (Lactoferrin) · Thyroglobulin · Alpha-lactalbumin Albumins Egg white Conalbumin · Ovalbumin · Avidin Serum albumin Human serum albumin · Bovine serum albumin · Prealbumin Other C-reactive protein · Lactalbumin (Alpha-lactalbumin) · Parvalbumin · Ricin see also disorders of globin and globulin proteins B proteins: BY STRUCTURE: membrane, globular (en, ca, an), fibrous

The original article states: “Globulin is one of the two types of serum proteins, the other being albumin.” However, according to Marieb & Hoehn (2007, pg. 649, Table 17.1), there are in fact, three types of serum proteins, including the aforementioned globulin, albumin, as well as fibrinogen.

Reference: Marieb, E. M., & Hoehn, K. (2007). Human Anatomy & Physiology (7th ed.). San Francisco, CA: Pearson Benjamin Cummings.

The revision "However...three types of serum proteins..." is incorrect. In the 2010 edition of Mareb & Hoehn, Table 17.1, pg. 636, fibrinogen is listed under the category "plasma proteins" not "serum proteins". Additionally, on pg. 652 of the text, serum is defined as "plasma minus the clotting proteins", of which fibrinogen is one (a clotting protein).

Reference: Marieb, E. M., & Hoehn, K. (2010). Human Anatomy & Physiology (8th ed.). San Francisco, CA: Pearson Benjamin Cummings.