Definition of "globulin" [glob•u•lin]

• Any of a class of proteins that are found extensively in blood plasma, milk, muscle, and plant seeds and that are insoluble in pure water and half saturated ammonium sulfate, soluble in dilute salt solution, and coagulable by heat. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Hundreds came to receive immune globulin, which is effective if taken within two weeks of exposure."
• "Ding et al. (Sept. 17 issue) 1 found that sex hormone-binding globulin, which is predominantly expressed in hepatocytes, may protect against type 2 diabetes."
• "Information Center for Sickle Cell and Thalassemic Disorder Since each alpha and beta has its own two protein molecules, Hemoglobin actually consists of four different protein molecules, also called globulin chains."