Theoretical Aspects of the U.V. Inactivation of Proteins Containing Disulfide Bonds

Equations are proposed for the estimation of quantum yields for cystine destruction and disulfide protein inactivation during u.v.‐irradiation in acidic and neutral solutions. The formulas permit a discussion of energy transfer from excited aromatic amino acids to cystines and/or of chemical reactions between excited tryptophans or tyrosines and cystines. The results are discussed with regard to general aspects of the photo‐biochemistry of enzymes.