Serum globulins

Not to be confused with globin or globular protein.

The globulins are a family of globular proteins that have higher molecular weights and water solubility values than the albumins. Some globulins are produced in the liver, while others are made by the immune system. Globulins, albumin, and fibrinogen are the major blood proteins. The normal concentration of globulins in the blood is about 2.6-4.6 g/dL.

The term "globulin" is sometimes used synonymously with "globular protein". However, albumins are also globular proteins, but are not globulins. All other serum globular proteins are globulins.

Types of globulins

All globulins fall into one of the following four categories:

Globulins can be distinguished from one another using serum protein electrophoresis.

Sizes

Globulins exist in various sizes. The lightest globulins are the alpha globulins, which typically have molecular weights of around 92 kDa, while the heaviest class of globulins are the gamma globulins, which typically weigh about 120 kDa. Being the heaviest, the gamma globulins are among the slowest to segregate in gel electrophoresis. Since they are immunologically active, they are also called "immunoglobulins".

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 class of globulins that are more soluble in ammonium sulfate than euglobulins. Pseudoglobulins are also soluble in pure water, while euglobulins are not.[2]

References

External links

  • Cornell
  • Medical Subject Headings (MeSH)

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