Definitions for "Globulin"
An albuminous body, insoluble in water, but soluble in dilute solutions of salt. It is present in the red blood corpuscles united with hæmatin to form hæmoglobin. It is also found in the crystalline lens of the eye, and in blood serum, and is sometimes called crystallin. In the plural the word is applied to a group of proteid substances such as vitellin, myosin, fibrinogen, etc., all insoluble in water, but soluble in dilute salt solutions.
A type of blood protein that is elevated in systemic inflammatory diseases such as lupus erythematosus and rheumatoid arthritis. Antibody molecules are a form of globulin protein.
In the late nineteenth century, it was discovered that there were two different proteins in serum. These proteins were named albumin and globulin. Since then the use of electrophoresis has aided in the identification of over 22 individual plasma proteins, many of which are subsets of globulin. As a result of the pre-dominance of these two protein types among total protein, an approximation of the globulin concentration can be easily determined by subtracting the albumin concentration from the total protein concentration. Globulin synthesis occurs in plasma cells, lymphocytes, and the liver. The major fractions of globulin are termed alpha, beta, and gamma. Alpha and beta globulins mainly carry various lipids, lipid-soluble hormones and vitamins, and other lipid-like substances in the plasma. Two other alpha globulins, ceruloplasmin and haptoglobin, are carriers of copper and hemoglobin, respectively. A beta globulin, transferrin, is an iron carrier. The gamma globulins consist primarily of the immunoglobulins.