Thermal stability studies on caprine and bovine lactoferrin. A comparative study (original) (raw)

LACTOFERRIN: ANALYSIS OF THE STRUCTURE PROFILE

The multitude of physiological processes in which the binding of iron ions takes part makes its mechanism worth investigating. The multiple sequence alignment method was applied to investigate the structure similarities of fi ve lactoferrin X-ray crystallographic structures and outline the differences and similarities between lactoferrin and serum transferrin. The results of this study provide useful insights into the mechanism of iron-binding of lactoferrin protein molecule.

Structure of iron saturated C-lobe of bovine lactoferrin at pH 6.8 indicates a weakening of iron coordination

Proteins, 2016

The bilobal lactoferrin is a ∼76kDa glycoprotein. It sequesters two Fe(3+) ions together with two CO3 (2-) ions. The C-terminal half (residues, Tyr342 - Arg689, C-lobe) of bovine lactoferrin (residues Ala1 - Arg689) was prepared by limited proteolysis using trypsin. Both C-lobe and intact bovine lactoferrin were saturated to 100%. Both of them retained up to nearly 85% of iron at pH 6.5. At pH 5.0, C-lobe retained 75% of iron whereas intact protein could retain only slightly more than 60%. At pH 4.0 both contained 25% iron and at pH 2.0 they were left with iron concentration of only 10%. The structure of iron saturated C-lobe was determined at 2.79 Å resolution and refined to Rcryst and Rfree factors of 0.205 and 0.273 respectively. The structure contains two crystallographically independent molecules, A and B. They were found to have identical structures with an r.m.s. shift of 0.5 Å for their C(α) atoms. A high solvent content of 66% was observed in the crystals. The average value...

Characteristics of bovine lactoferrin powders produced through spray and freeze drying processes

International journal of biological macromolecules, 2017

Bovine lactoferrin (LFb) powders were produced using spray drying and freeze drying. Industrially obtained fresh liquid-LFb was used as starting material. The antioxidant capacity, solubility in water, moisture sorption behaviour, the extent of denaturation and changes in the secondary structural features of spray-dried (SDLFb) and freeze-dried bovine lactoferrin (FDLFb) powders were determined. The residual moisture content, water activity, particle size and amorphous/crystalline nature of the SDLFb and FDLFb were also measured. Results showed that both SDLFb and FDLFb powders had negligible denaturation and conformation changes compared to the liquid-LFb. Both SDLFb and FDLFb showed type II sorption behaviour with almost identical monolayer moisture content. The SDLFb powders were amorphous in nature with >98% solubility in water. The antioxidant activity of SDLFb was similar to that of the liquid-LFb while it was ∼6% less in FDLFb. Based on the residual moisture content, water...