Interaction of lactoferrin with ascorbate and the relationship with bleomycin-dependent DNA damage

Area of Science:

• Biochemistry
• Molecular Biology
• Nutritional Science

Background:

• Oxidative stress contributes to DNA damage.
• Malondialdehyde (MDA) is a marker of lipid peroxidation.
• Bovine lactoferrin (bLf) and ascorbate (Asc) are known antioxidants.

Purpose of the Study:

• To investigate the interaction between bovine lactoferrin (bLf) and ascorbate (Asc).
• To determine if bLf and Asc exhibit synergistic antioxidant effects.
• To characterize the binding interaction between bLf and Asc.

Main Methods:

• Malondialdehyde (MDA) formation assay in the presence of DNA, bleomycin (BLM), and Fe2+ or Asc.
• Enzymatic hydrolysis of bLf (pepsin, trypsin).
• Gel filtration chromatography (Sephadex G75) to assess binding.

Main Results:

• bLf significantly inhibited MDA formation in the presence of Asc.
• Inhibitory effect of bLf on MDA formation was not affected by carbonate or oxalate ions.
• Hydrolysates of bLf retained inhibitory activity.
• Filtrate of bLf-Asc solution showed inhibition, unlike bovine serum albumin-Asc.
• Gel filtration indicated a binding interaction with an estimated 87 mol of Asc bound per mole of bLf.

Conclusions:

• Bovine lactoferrin (bLf) interacts with ascorbate (Asc), enhancing its antioxidant properties.
• The interaction between bLf and Asc is specific and involves direct binding.
• bLf demonstrates protective effects against oxidative damage, potentially through its interaction with Asc.