Isoleucine, which is abbreviated as the 3-letters Ile or the single letter I, is one of the 20 amino acids that make up proteins in our body. Isoleucine’s R-group is a branched 4-carbon structure or sec-butyl group, with the carbons arranged in a cup or bowl-like structure. Since this R-group is non-polar, isoleucine is also a non-polar, hydrophobic amino acid, with a neutral charge at physiological pH.

Key Points

  • Isoleucine
    • Abbreviations
      • Ile, I
    • Chemical Structure
    • R-Group: Sec-butyl -CH(CH3)-CH2-CH3
    • Polarity
      • Non-polar (lipid soluble/hydrophobic)
    • Charge at pH 7
      • Neutral (0)