| Aromatic amino acids are relatively
nonpolar. To different degrees, all aromatic amino acids absorb
ultraviolet light. Tyrosine and tryptophan absorb more than do phenylalanine;
tryptophan is responsible for most of the absorbance of ultraviolet
light (ca. 280 nm) by proteins. Tyrosine is the only one of the aromatic
amino acids with an ionizable side chain. Tyrosine is one of three hydroxyl
containing amino acids. |
Very
hydrophobic
