Fluorescence of pyoverdin in response to iron and other common well water metals.
When the fluorescent siderophore pyoverdin (produced by Pseudomonas aeruginosa) binds to a metal ion the fluorescence changes. A pyoverdin solution (in 0.1 M acetate buffer, pH 5.0) was placed in the microwells of a 96-well plate and varying concentrations of the metal cations Al(3+), Ca(2+), Cu(2+), Fe(2+), Fe(3+), Mn(2+), Mg(2+), and Zn(2+) were added. The fluorescence of pyoverdin 60 sec after the addition of an equimolar concentration of metal indicated: (1) no change for Ca(2+), Fe(2+), Mn(2+), Mg(2+), and Zn(2+); (2) a small increase (109%) for Al(3+); (3) decreases in fluorescence for Cu(2+) (83%) and for Fe(3+) (66%). The fluorescence of pyoverdin 24 hr after the addition of equimolar metal indicated: 1) very little change for Ca(2+), Mn(2+), Mg(2+), and Zn(2+); 2) a very large (270%) increase in fluorescence due to Al(3+); 3) an increase (113%) due to Cu(2+); 4) large decreases in fluorescence for both Fe(2+) (15%) and Fe(3+) (0%). Thus, for an iron assay using a free solution of pyoverdin, even with a short (60 sec.) reaction time there can be interference due to Cu(2+), and interference due to high levels of Al(3+).
Biological and Agricultural Engineering Department, Driftmier Engineering Center, University of Georgia, Athens, Georgia, USA.
Michael F
MF
Yoder
William S
WS
Kisaalita
D002412:Cations; D005453:Fluorescence; D007501:Iron / Q000378:metabolism*; D008670:Metals / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014867:Water / Q000737:chemistry*
D002412:Cations; D008670:Metals; D009842:Oligopeptides; D014867:Water; C042453:pyoverdin; D007501:Iron; D010100:Oxygen