Tyrosine
Tyrosine — A conditionally essential aromatic amino acid (Tyr, Y) involved in phosphorylation-based cell signaling and catecholamine synthesis.
What Is Tyrosine?
Tyrosine (Tyr, Y) is an aromatic amino acid with a phenol side chain (MW: 181.19 Da, pKa ~10.1). It is a key residue in receptor-ligand interactions, phosphorylation-based signaling, and peptide UV detection. The N-terminal tyrosine in opioid peptides (enkephalins, endorphins, dynorphin) is absolutely required for mu-opioid receptor binding.
Roles in Peptide Research
- Opioid pharmacophore: Tyr1 is the essential "message" residue in all opioid peptide sequences
- Phosphorylation: Tyrosine kinase substrates; phospho-Tyr detection is central to signal transduction studies
- UV absorbance: Absorbs at 280 nm (ε = 1,490 M⁻¹cm⁻¹), contributing to peptide concentration measurement
- Iodination: Tyrosine is the site for radioiodination (I-125) labeling of peptides for binding assays
Frequently Asked Questions
What is Tyrosine?
A conditionally essential aromatic amino acid (Tyr, Y) involved in phosphorylation-based cell signaling and catecholamine synthesis.
Why is Tyrosine important in peptide research?
Tyrosine 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.