TY - JOUR
T1 - Tryptophan fluorescence intensity and anisotropy decays of human serum albumin resulting from one-photon and two-photon excitation
AU - Lakowicz, Joseph R.
AU - Gryczynski, Ignacy
N1 - Funding Information:
The authors acknowledge support from the NationaI Science Foundation (DIR-8710401 and DMB-88049311, the National Institutes of Health (RR-04800 and RR-07510) and. the Medical BiotechnoIogy Center and Graduate School at the University of Maryland. We thank Dr. Badri Maliwal for his assistance with the preparation of the samples.
PY - 1992/11
Y1 - 1992/11
N2 - We measured the emission spectra, intensity decays and anisotropy decays of the single tryptophan residue of human serum albumin (HSA) resulting from one-photon (295-298 nm) and two-photon (590-596) excitation. The emission spectra and intensity decays were independent of the mode of excitation. The anisotropy decays were superficially similar for one- and two-photon excitation. However, upon consideration of the different orientation photoselection for one- and two-photon excitation, the anisotropy data reveal different angles between the absorption and emission oscillators for one-photon and two-photon excitation. This result suggests different relative one-photon and two-photon cross-sections for the 1La and 1Lb transitions of the indole residue. This first report of the time-resolved anisotropy decay of a protein resulting from two-photon excitation suggests that such measurement will yield insights into the complex photophysical properties of tryptophan residues in proteins.
AB - We measured the emission spectra, intensity decays and anisotropy decays of the single tryptophan residue of human serum albumin (HSA) resulting from one-photon (295-298 nm) and two-photon (590-596) excitation. The emission spectra and intensity decays were independent of the mode of excitation. The anisotropy decays were superficially similar for one- and two-photon excitation. However, upon consideration of the different orientation photoselection for one- and two-photon excitation, the anisotropy data reveal different angles between the absorption and emission oscillators for one-photon and two-photon excitation. This result suggests different relative one-photon and two-photon cross-sections for the 1La and 1Lb transitions of the indole residue. This first report of the time-resolved anisotropy decay of a protein resulting from two-photon excitation suggests that such measurement will yield insights into the complex photophysical properties of tryptophan residues in proteins.
KW - Human serum albumin
KW - One- and two-photon excitation
KW - Tryptophan anisotropy decay
KW - Tryptophan fluorescence intensity decay
UR - http://www.scopus.com/inward/record.url?scp=0026497905&partnerID=8YFLogxK
U2 - 10.1016/0301-4622(92)87017-D
DO - 10.1016/0301-4622(92)87017-D
M3 - Article
C2 - 1467440
AN - SCOPUS:0026497905
SN - 0301-4622
VL - 45
SP - 1
EP - 6
JO - Biophysical Chemistry
JF - Biophysical Chemistry
IS - 1
ER -