Prosthetic Group

prosthetic group

[präs′thed·ik ′grüp]

(biochemistry)

A characteristic nonamino acid substance that is strongly bound to a protein and necessary for the protein portion of an enzyme to function; often used to describe the function, as in hemeprotein for hemoglobin.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Prosthetic Group

 

an organic and nonprotein compound that forms a part of conjugated proteins. In enzymatic catalysis the prosthetic group is usually referred to as a coenzyme. Coenzymes are firmly bonded to the protein part of a biocatalyst by an apoenzyme and remain affixed to the protein molecule for the duration of the catalysis; examples of coenzymes include lipoic acid, riboflavin, biotin, and hemes.

Carrier coenzymes differ from prosthetic groups. The activity of carrier coenzymes is associated with their transfer from one enzyme molecule to another. However, this differentiation is often arbitrary, since the same compound (for example, flavine-adenine dinucleotide) can sometimes act like a typical dissociating coenzyme, while at other times it remains firmly bonded to the protein.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.