monoamine oxidase

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An enzyme in the cells of most tissues that catalyzes the oxidation of monoamines such as norepinephrine and serotonin.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun biochemistry Either of two enzymes, found in the outer membrane of mitochondria, that degrade biogenic amines and are thus responsible for the destruction of transmitter substances at neuronal synapses.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an enzyme that catalyzes the oxidation of many body compounds (e.g., epinephrine and norepinephrine and serotonin)