Iron acquisition from transferrin and lactoferrin by Pseudomonas aeruginosa pyoverdin.
Growth of Pseudomonas aeruginosa ATCC 15692 was promoted when the strain was cultured in an iron-depleted succinate medium, supplemented with transferrin at 30%, 60% and 100% and lactoferrin at 60% and 100% iron-saturation. No significant differences between cell growth and pyoverdin production were observed when transferrin iron saturation was increased from 30% to 100%; however, cell growth and pyoverdin production were strongly dependent on lactoferrin iron saturation. Lower lactoferrin iron saturation (< 30%) resulted in more pyoverdin production and reduced cell growth. Incubation of pyoverdin (1.0 microM) with 10.0 microM transferrin (30%, 60% and 100% iron-saturated) or lactoferrin (60% and 100% iron-saturated) led to quenching of pyoverdin fluorescence. Also, 24 h incubation of pyoverdin (20.0 microM) with these two proteins (20.0 microM, 30%, 60% and 100% iron-saturated transferrin and 60% and 100% iron-saturated lactoferrin) at 25 degrees C resulted in increased absorbance at 460 nm. Both the fluorescence quenching and absorbance increases were iron-saturation-dependent. Taken together, these results support the conclusion that at physiological pH, P. aeruginosa pyoverdin can acquire from partially iron-saturated transferrin or lactoferrin.
Jeong
Byeong C
BC
School of Biological Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Hawes
Chris
C
School of Biological and Molecular Sciences, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK.
Bonthrone
Karen M
KM
School of Biological Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Macaskie
Lynne E
LE
School of Biological Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D007781:Lactoferrin / Q000378:metabolism*; D009842:Oligopeptides; D010860:Pigments, Biological / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000378:metabolism*; D014168:Transferrin / Q000378:metabolism*
D009842:Oligopeptides; D010860:Pigments, Biological; D014168:Transferrin; C042453:pyoverdin; D007501:Iron; D007781:Lactoferrin