Evaluation of different methods for determination of the iron saturation level in bovine lactoferrin.
Lactoferrin (Lf) samples with ca. 25%, 50%, 75%, 85% and 100% iron saturation were prepared for the purpose of evaluating Chromametry, Differential Scanning Calorimetry (DSC) and Circular Dichroism (CD) spectropolarimetry for their suitability in determining the iron saturation level. Numerical values for colour from Chromametry, enthalpy change of denaturation (ΔHcal) from DSC and molar ellipticities from CD were statistically analysed to evaluate their correlation with the level of iron saturation in Lf. Linear regression analysis of colour coordinates Chroma (C(∗)) and hue (h°) angle on percentage iron saturation level of Lf showed that the values can be used to estimate the iron saturation level. The ΔHcal for the iron saturated peak and the CD ellipticities in the 310-340 nm region provided reliable data for the estimation of iron saturation level of Lf up to 75%. Mono- and di-saturated Lf displayed the same thermal stability and very similar tertiary structures.
The University of Queensland, School of Agriculture and Food Sciences, Brisbane, QLD 4072, Australia. Electronic address: h.rai@uq.edu.au.
Huma
H
Bokkhim
The University of Queensland, School of Agriculture and Food Sciences, Brisbane, QLD 4072, Australia. Electronic address: trannguyenhatrang@yahoo.com.
Trang
T
Tran
The University of Queensland, School of Agriculture and Food Sciences, Brisbane, QLD 4072, Australia. Electronic address: n.bansal@uq.edu.au.
Nidhi
N
Bansal
The University of Queensland, School of Chemistry and Molecular Biosciences, Brisbane, QLD 4072, Australia. Electronic address: l.grondahl@uq.edu.au.
Lisbeth
L
Grøndahl
The University of Queensland, School of Agriculture and Food Sciences, Brisbane, QLD 4072, Australia. Electronic address: b.bhandari@uq.edu.au.
Bhesh
B
Bhandari
D000818:Animals; D002152:Calorimetry, Differential Scanning / Q000379:methods*; D002417:Cattle; D002942:Circular Dichroism / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D007501:Iron / Q000737:chemistry*; D007781:Lactoferrin / Q000737:chemistry*; D011487:Protein Conformation; D055550:Protein Stability
D007501:Iron; D007781:Lactoferrin
Colour space parameters; Ellipticity; Enthalpy of denaturation; Iron saturation; Lactoferrin; Polar coordinates