Structures of buffalo and mare lactoferrins. Similarities, differences, and flexibility.

This research article focuses on studying the structure of lactoferrin, a protein responsible for defense against microbial infection, in buffalo and mare mammals. The study compares and contrasts the similarities, differences, and flexibility of these proteins.

Lactoferrin and Its Role

• Lactoferrin (Lf) is an iron-binding glycoprotein found in the external secretions (like milk) and neutrophilic leucocytes (a type of white blood cells) of mammals.
• Its primary role is to defend against microbial infection. This is primarily achieved by lactoferrin’s ability to sequester, or withhold, iron, which is essential for microbial growth. By reducing the available iron, lactoferrin inhibits the growth or replication of infectious microorganisms.
• Aside from this, lactoferrin is also known to perform other functions, including immunomodulation (regulating the immune response) and cell growth regulation.

Structure of Lactoferrin

• Lactoferrin is a protein with a molecular mass of about 80 kDa (kilodaltons), a unit used to measure the mass of molecules.
• Structurally, the protein folds into two globular lobes: the N-lobe consisting of the N-terminal half of the polypeptide chain and the C-lobe consisting of the C-terminal half of the polypeptide chain. The term ‘terminal’ here refers to the ends of a polypeptide chain; polypeptides are chains of amino acids, which are the building blocks of proteins.
• These two lobes are connected by a small peptide chain which consists of 10-12 residues, arranged in a 310-helical structure. A residue usually refers to a specific monomer in the polymeric chain of a polysaccharide, protein or nucleic acid.
• Further, each lobe is divided into two domains, and each domain contains a single iron binding site, located in the interdomain cleft (space or gap). This is where the iron sequestration activity of the protein occurs.

The research focus on comparing the structure of lactoferrin in buffaloes and mares extends our knowledge about this protein in different mammalian species, which might help in better understanding its functions and potential applications in human health and disease control.