Journal of Thermal Analysis and Calorimetry

, Volume 103, Issue 1, pp 41–47 | Cite as

Calorimetric and Raman investigation of cow’s milk lactoferrin

  • Michele Iafisco
  • Ismaela Foltran
  • Michele Di Foggia
  • Sergio Bonora
  • Norberto Roveri


Lactoferrin (LF), a non-heme iron-binding protein of blood plasma and milk with antioxidant, cariostatic, anticarcinogenic, and anti-inflammatory properties, has been studied by differential scanning calorimetry (DSC) and Raman spectroscopy over a wide pH range (4.0–9.0). Using these two techniques, the modifications in the quantity of iron bounded in the cow’s milk LF and in the secondary structures, as a function of pH and heating, have been evaluated. DSC curves showed higher value of denaturation temperatures and enthalpy changes when LF was saturated with iron (holo-form) than when it was in its unsaturated form (apo-form). The denaturation curves of the protein solutions at pH ≥ 5.5 confirming that LF is a mix of apo- and holo-forms; on the contrary at pH 4.0, the holo-form is practically absent. Spectroscopic investigation showed that, as a function of pH, the content of α-helix increases up to pH 7.4, followed by a small decrease by further pH increase. The β-sheet percentage exhibits the opposite behavior, while the random-coil and turn structures do not change noticeably. In contrast, after heat-induced denaturation, strong variations were observed in the secondary structure, with an evident increase of β-sheet and decrease of the α-helix percentage. Finally, both thermal and spectroscopic analysis pointed out that the structure of cow’s milk LF is strictly sensible to pH variation and it has the highest thermal stability at physiological pH.


Lactoferrin Raman spectroscopy Differential scanning calorimetry Protein denaturation Protein biophysics 



This research was financially supported by MiPAAF (Ministero delle Politiche Agricole, Alimentari e Forestali) “FINALE-QUALIFU” Project D.M.2087/7303/09. We acknowledge the Inter University Consortium for Research on Chemistry of Metals in Biological Systems (C.I.R.C.M.S.B) and the research project “Nanoparticelle multifunzionali per la terapia dei carcinomi: studi in vitro e in vivo in modelli sperimentali” funded by Regione Piemonte (Ricerca Sanitaria Finalizzata 2009). M.I. is recipient of a fellowship from Regione Piemonte.


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2010

Authors and Affiliations

  • Michele Iafisco
    • 1
    • 2
  • Ismaela Foltran
    • 1
    • 2
  • Michele Di Foggia
    • 3
  • Sergio Bonora
    • 3
  • Norberto Roveri
    • 1
  1. 1.Dipartimento di Chimica “G. Ciamician”, Alma Mater StudiorumUniversità di BolognaBolognaItaly
  2. 2.Dipartimento di Scienze MedicheUniversità del Piemonte OrientaleNovaraItaly
  3. 3.Dipartimento di Biochimica ‘G. Moruzzi’ Alma Mater StudoriumUniversità di BolognaBolognaItaly

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