Summary

Aspartate, which abbreviates to the 3-letter Asp or 1-letter D, is one of the 20 amino acids that make up proteins in our body. Aspartate’s R-group consists of a carboxylic acid at the end of a short, 1-carbon chain. Due to this carboxyl group, aspartate is a polar, hydrophilic amino acid. The carboxylic acid can also act as a proton donor, making Aspartate an acidic, negatively charged amino acid at physiological pH. 

Key Points

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