l-Me-thion-yl-l-tyrosine monohydrate

Area of Science:

• Biochemistry
• Chemical Crystallography
• Physical Chemistry

Background:

• Protein oxidation is a critical area of study, with methionine (Met) and tyrosine (Tyr) residues being particularly susceptible to oxidation.
• Understanding the oxidation mechanisms of peptides containing Met and Tyr is essential for various biochemical and medical applications.
• The oxidation of the Met-Tyr dipeptide remains incompletely understood, with proposed intramolecular electron transfer mechanisms.

Purpose of the Study:

• To elucidate the crystal structure and absolute configuration of l-Met-l-Tyr monohydrate.
• To investigate the zwitterionic nature of the Met-Tyr dipeptide.
• To explore the potential role of the zwitterionic state and solvent interactions in the oxidation of the Met-Tyr dipeptide.

Main Methods:

• Single-crystal X-ray diffraction was used to determine the structure and absolute configuration of l-Met-l-Tyr monohydrate.
• Analysis of intermolecular interactions, including hydrogen bonding, within the crystal lattice.

Main Results:

• The crystal structure of l-Met-l-Tyr monohydrate was successfully determined, providing insights into its molecular conformation.
• Evidence for the zwitterionic nature of the dipeptide was obtained from structural analysis.
• Identification of extensive hydrogen bonding networks (N-H⋯O, C-H⋯O, O-H⋯S, O-H⋯O) within the crystal structure.

Conclusions:

• The elucidated structure of l-Met-l-Tyr monohydrate provides a foundation for understanding its chemical properties.
• The zwitterionic state of the dipeptide and its interactions with the solvent environment are hypothesized to be key factors in its oxidation.
• Further studies are warranted to confirm the role of zwitterionic character and solvent interactions in methionine-tyrosine dipeptide oxidation.