• synonyms


[ahy-suh-loo-seen, -sin]
noun Biochemistry.
  1. a crystalline amino acid, C6H13O2, occurring in proteins, that is essential to the nutrition of humans and animals. Abbreviation: Ile; Symbol: I
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Origin of isoleucine

First recorded in 1900–05; iso- + leucine
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for isoleucine


  1. an essential amino acid that occurs in proteins and is formed by protein hydrolysis
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

isoleucine in Medicine


  1. An essential amino acid that is isomeric with leucine.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

isoleucine in Science


  1. An essential amino acid. Chemical formula: C6H13NO2. See more at amino acid.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.