Heme-tryptophan relationships in hemoglobin explored by frequency-domain time-resolved fluorescence at 10-GHz resolution

Enrico Bucci, Zygmunt Gryczynski, Enrico Gratton, Todd Tenenholz

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations

Abstract

The time-resolved fluorescence spectroscopy of human and bovine oxy- and deoxyhemoglobins was measured in either 0.03 M phosphate buffer or 0.03 M borate buffer between pH 6.5 and 9.2. A frequency resolved fluorometer was used with bandwidth up to 10 GHz. Excitation was at 294 nm, the emission was monitored through a broad band interference filter centered at 335 nm, coupled to a cut-off filter at 316 nm. In all cases, the best simulations were obtained with two discrete exponential decays, one near 30 ps, and the other of several hundred ps. In human hemoglobin, the longer component showed a substantial lengthening upon removal of oxygen. In bovine hemoglobin, the shorter component decreased upon deoxygenation. It was possible to infer that the shorter lifetimes originated from the average intrachain distances. However, the hemes at this longer distance would become the main acceptors of energy transfer only when the energy transfer at intrasubunit distance is inhibited. It is suggested that this is due to the presence of `disordered' heme in the system.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Int Soc for Optical Engineering
Pages784-791
Number of pages8
ISBN (Print)0819407860
StatePublished - 1 Jan 1992
EventTime-Resolved Laser Spectroscopy in Biochemistry III - Los Angeles, CA, USA
Duration: 20 Jan 199222 Jan 1992

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume1640
ISSN (Print)0277-786X

Other

OtherTime-Resolved Laser Spectroscopy in Biochemistry III
CityLos Angeles, CA, USA
Period20/01/9222/01/92

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  • Cite this

    Bucci, E., Gryczynski, Z., Gratton, E., & Tenenholz, T. (1992). Heme-tryptophan relationships in hemoglobin explored by frequency-domain time-resolved fluorescence at 10-GHz resolution. In Proceedings of SPIE - The International Society for Optical Engineering (pp. 784-791). (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 1640). Publ by Int Soc for Optical Engineering.