Reactions contained PS (10 μM) plus 100 mM NaNO2 plus 1 mM N-acetyl-tyrosine ethyl ester. The following wavelengths were used MB, 660 nm; RB, 540 nm; TPPS4, 415 nm; LC15, 415 nm and 100 J/cm2 of each. The “in format” had all components present during light, while for the “after format” the N-acetyl-tyrosine ethyl ester was added after the end of illumination.