> U=p-acetylphenylalanine. C was labeled with Alexa Fluor 594 C5 maleimide. U was labeled with Alexa Fluor 488 C5 hydroxylamine GCDKIIHLTDDSFDTDVLKADGAILVDFWAEWSGPSKMIAPILDEIADEYQGKLTVAKLNIDQNPGTAPKYGIRGIPTLLLFKNGEVAATKVGALSKGQLKEFLDANUA
