globulin

n. type of protein found in plant and animal tissues

Globulin is one of the two types of serum proteins, the other being albumin. This generic term encompasses a heterogeneous series of families of proteins, with larger molecules and less soluble in pure water than albumin, which migrate less than albumin during serum electrophoresis. 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 globulinsAlpha 2 globulinsBeta globulinsGamma globulins (one group of gamma globulins are immunoglobulins, that function as antibodies)
See more at Wikipedia.org...

n. globulin, type of protein found in plant and animal tissues

(n.)
An albuminous body, insoluble in water, but soluble in dilute solutions of salt. It is present in the red blood corpuscles united with haematin to form haemoglobin. 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.
  

Noun
1. a family of proteins found in blood and milk and muscle and in plant seed
(hypernym) simple protein
(hyponym) alpha globulin