Aspartic Acid
Aspartic Acid — An acidic amino acid (Asp, D) with a carboxyl side chain. Involved in the urea cycle and gluconeogenesis.
What Is Aspartic Acid?
Aspartic acid (Asp, D) is a negatively charged amino acid with a carboxyl side chain (pKa ~3.65, MW: 133.10 Da). It forms salt bridges with positively charged residues (Arg, Lys), coordinates metal ions, and is a key residue in enzyme active sites. Its close relative asparagine (Asn, N) is the primary site of deamidation.
Stability Implications
- Asp-Pro cleavage: The Asp-Pro peptide bond is the most acid-labile amide bond, cleaving at pH < 3 with heating
- Aspartimide formation: Side reaction during SPPS where Asp forms a cyclic imide, producing beta-aspartate and D-aspartate impurities
- Deamidation product: Asp and isoAsp are the products of asparagine deamidation, the major chemical degradation of Asn-containing peptides
Frequently Asked Questions
What is Aspartic Acid?
An acidic amino acid (Asp, D) with a carboxyl side chain. Involved in the urea cycle and gluconeogenesis.
Why is Aspartic Acid important in peptide research?
Aspartic Acid is a fundamental concept in amino acid as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.