Related Experiment Video
Updated: Jul 5, 2026

Expression and Purification of Nuclease-Free Oxygen Scavenger Protocatechuate 3,4-Dioxygenase
Published on: November 8, 2019
Quantitative determination of singlet oxygen generated by excited state aromatic amino acids, proteins, and
Khin K Chin1, Colleen C Trevithick-Sutton, Jeremy McCallum
1Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
Abstract:
Singlet oxygen quantum yields generated by excited state aromatic amino acids (tryptophan, tyrosine, phenylalanine), N-acetylated amino acids (N-acetyl-tryptophan, N-acetyl-tyrosine, N-acetyl-phenylalanine), and from selected proteins and immunoglobulins have been quantified by time-resolved phosphorescence measurements. A small, but significant, quantum yield found for proteins and immunoglobulins demonstrates that molecular oxygen can diffuse through the polypeptide matrix and can be sensitized by residues buried within the folds of protein structure.

