Glutamate, which abbreviates to the 3-letter Glu or 1-letter E, is one of the 20 amino acids that make up proteins in our body. Glutamate’s R-group is a carboxylic acid at the end of a longer, 2-carbon chain. Due to its two oxygens, glutamate is a polar, hydrophilic amino acid. The carboxylic acid can also act as a proton donor, making glutamate an acidic, negatively charged amino acid at physiological pH. 

Key Points

  • Glutamate
    • Also known as Glutamic Acid
    • Abbreviations
      • Glu, E
    • Chemical Structure
    • R-Group: -CH2-CH2-Carboxyl
      • Carboxyl
        • Contrast vs. Glutamine (which has amide instead of carboxyl)
        • “-ate” ending denotes ionic form of carboxylic acid
      • 2 bridging methylene carbons (-CH2-CH2-)
        • Contrast vs. Aspartate (only 1 bridging carbon)
    • Polarity
      • Polar (water soluble/hydrophilic)
    • Acidity/Basicity
      • Acidic
      • pKa = 4 (rounded)
    • Charge at pH 7
      • Negative (-)
    • Other Information
      • Called Glutamic Acid when deprotonated