TY - JOUR
T1 - Time-resolved emission spectra of hemoglobin on the picosecond time scale
AU - Bucci, Enrico
AU - Malak, Henryk
AU - Fronticelli, Clara
AU - Gryczynski, Ignacy
AU - Laczko, Gabor
AU - Lakowicz, Joseph R.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1988/12
Y1 - 1988/12
N2 - We used front-face illumination to examine the steady-state and time-resolved emission from the intrinsic tryptophan emission of human hemoglobin (Hb). Experimental conditions were identified which eliminated all contributions of scattered light. The sensitivity obtained using front-face optics was adequate to allow measurement of the wavelength-dependent frequency response of the emission to 2 GHz. The intensity decays displayed pico- and nanosecond components in the emission at all wavelengths from 315 to 380 nm. The contribution of the picosecond component decreased from 72 to 37% over this range of wavelengths. Frequency-domain measurements were used to calculate the time-resolved emission spectra and decay-associated emission spectra. These spectra indicate that the picosecond components of the emission display maxima near 320 nm, whereas the nanosecond components are centered at longer wavelengths near 335 nm. The nanosecond components appear to be due to residual impurities which remain even in highly purified samples of Hb. However, we cannot eliminate the possibility that some of these components are due to Hb itself.
AB - We used front-face illumination to examine the steady-state and time-resolved emission from the intrinsic tryptophan emission of human hemoglobin (Hb). Experimental conditions were identified which eliminated all contributions of scattered light. The sensitivity obtained using front-face optics was adequate to allow measurement of the wavelength-dependent frequency response of the emission to 2 GHz. The intensity decays displayed pico- and nanosecond components in the emission at all wavelengths from 315 to 380 nm. The contribution of the picosecond component decreased from 72 to 37% over this range of wavelengths. Frequency-domain measurements were used to calculate the time-resolved emission spectra and decay-associated emission spectra. These spectra indicate that the picosecond components of the emission display maxima near 320 nm, whereas the nanosecond components are centered at longer wavelengths near 335 nm. The nanosecond components appear to be due to residual impurities which remain even in highly purified samples of Hb. However, we cannot eliminate the possibility that some of these components are due to Hb itself.
KW - Hemoglobin
KW - Picosecond spectroscopy
KW - Time-resolved emission
KW - Tryptophan fluorescence
UR - http://www.scopus.com/inward/record.url?scp=0024259263&partnerID=8YFLogxK
U2 - 10.1016/0301-4622(88)87006-6
DO - 10.1016/0301-4622(88)87006-6
M3 - Article
C2 - 3251568
AN - SCOPUS:0024259263
SN - 0301-4622
VL - 32
SP - 187
EP - 198
JO - Biophysical Chemistry
JF - Biophysical Chemistry
IS - 2-3
ER -