Definition of "phosphodiesterase" []

• Any of a class of enzymes that catalyze the cleaving of phosphodiester bonds, such as those between nucleotides in nucleic acids, to produce smaller nucleotide units. (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.

• "However, this works in reverse as well; an erection softens as soon as another enzyme called phosphodiesterase starts to degrade the cGMP molecules."
• "Viagra's active compound, sildenafil, works by inhibiting an enzyme called phosphodiesterase-5 (PDE5)."
• "The drug, manufactured by pharmaceutical giant Eli Lilly and the third in a new class of drugs known as phosphodiesterase (PDE) inhibitors, was originally approved in 2003 for use on an "as you need it" basis."