Characterization of Korean native goat lactoferrin

Area of Science:

• Biochemistry
• Proteomics
• Animal Science

Background:

• Lactoferrin, a key milk protein, possesses antimicrobial and immunomodulatory functions.
• Characterizing lactoferrin from diverse animal sources like the Korean native goat (Capra hircus) is crucial for understanding its variations and potential applications.

Purpose of the Study:

• To purify lactoferrin from Korean native goat colostrum.
• To characterize its biophysical properties, including molecular mass, iron saturation, and secondary structure.
• To investigate its heparin-binding affinity and compare it with other species.

Main Methods:

• Ion-exchange chromatography (CM-Toyopearl 650M) and affinity chromatography (AF-Heparin Toyopearl 650M) for purification.
• Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot for molecular mass determination.
• Spectroscopic analysis for iron saturation.
• Circular dichroism (CD) spectroscopy for secondary structure analysis.
• Synthetic peptide analysis for heparin-binding interactions.

Main Results:

• Purified Korean native goat lactoferrin with an estimated molecular mass of 82 kDa.
• Iron saturation was determined to be 30% via spectroscopic analysis.
• Circular dichroism revealed a secondary structure composition of 24.5% alpha-helix, 36.0% beta-structure, 13.5% beta-turn, and 26.0% unordered structure.
• Heparin binding affinity was found to be similar to bovine lactoferrin but lower than human lactoferrin.
• A specific peptide (residues 22-31, WQRRMRKLGA) demonstrated positive heparin-binding ability.

Conclusions:

• Successfully purified and characterized lactoferrin from Korean native goat colostrum.
• The structural and binding properties of goat lactoferrin provide insights into its functional characteristics.
• Identification of a heparin-binding peptide sequence offers potential for targeted applications or further structural studies.