Fluorescence of tyrosine and tryptophan in proteins using one- and two-photon excitation.
We examined the emission spectra of tyrosine- and tryptophan-containing proteins using one-photon (270-310 nm) and two-photon (565-610 nm) excitation. Emission spectra for two-photon excitation of native and denatured human serum albumin and of three purine nucleoside phosphorylases indicated an absence of the tyrosine emission normally seen for one-photon excitation below 290 nm. We examined the one-photon and two-photon excitation spectra of tyrosine-tryptophan mixtures to determine the origin of selective excitation of the tryptophan residues. These results confirmed a short-wavelength shift of the tyrosine two-photon excitation spectrum relative to that of tryptophan, as recently reported by Rehms and Callis (1993) Chem. Phys. Lett. 208, 276-282.
Kierdaszuk
B
B
Department of Biological Chemistry, University of Maryland School of Medicine, Baltimore 21201, USA.
Gryczynski
I
I
Modrak-Wojcik
A
A
Bzowska
A
A
Shugar
D
D
Lakowicz
J R
JR
D000818:Animals; D002417:Cattle; D006801:Humans; D010777:Photochemistry; D017785:Photons; D011506:Proteins / Q000737:chemistry* / Q000528:radiation effects; D011683:Purine-Nucleoside Phosphorylase / Q000737:chemistry / Q000528:radiation effects; D012709:Serum Albumin / Q000737:chemistry / Q000528:radiation effects; D013050:Spectrometry, Fluorescence; D014364:Tryptophan / Q000737:chemistry / Q000528:radiation effects; D014443:Tyrosine / Q000737:chemistry / Q000528:radiation effects
D011506:Proteins; D012709:Serum Albumin; D014443:Tyrosine; D014364:Tryptophan; D011683:Purine-Nucleoside Phosphorylase