Abstract
A new spectroscopic technique is presented for obtaining infraredlike spectra of the binding sites of Ca2+ and other metals in biological macromolecules. The technique, based on the Ca(2+)-like binding properties of Gd3+, utilizes vibronic side bands (VSB) that appear in Gd3+ fluorescence. In the fluorescence spectrum of Gd3+, the separation in photon frequency between a VSB and its electronic origin at approximately 32,150 cm-1 (approximately 311 nm) is a direct measure of the vibrational frequency of a ligand coordinated to Gd3+ ion. As a consequence, the VSB are uncomplicated by molecular vibrations distant from the Gd3+ binding site. The vibrational spectra resulting from the VSB of Gd3+ coordinated to a Ca2+ binding protein, a phospholipid, and DNA are presented.
Original language | English (US) |
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Pages (from-to) | 1040-1049 |
Number of pages | 10 |
Journal | Biophysical journal |
Volume | 59 |
Issue number | 5 |
DOIs | |
State | Published - 1991 |
Externally published | Yes |
ASJC Scopus subject areas
- Biophysics