A computational exploration of surfactant proteins and their properties

Pulmonary surfactant (PS) is a vital lipid-protein mixture in the lungs that facilitates healthy breathing and defends against airborne pathogens. PS is comprised of two types of surfactant proteins (SP), the large hydrophilic surfactant proteins SP-A and SP-D that are mainly involved in the innate immune response of the lung, and the small hydrophobic surfactant proteins SP-B and SP-C which help regulate the phase transition of the lipid layer. These components of the PS system are essential for maintaining the unique functions of the lung. SP-A and SP-D are immunoproteins that can bind numerous viruses, yeasts, and bacteria by interacting with surface glycans to tag for phagocytosis. Surfactant proteins exist at various biological interfaces including the air/liquid interface in the lungs. Much of their properties and interactions remain elusive to us. More studies need to be conducted, especially computationally. Utilizing computational models of these surfactant proteins elucidates their critical structural and mechanistic properties. We will discuss some of these surfactant proteins and their properties through a computational lens incorporating methods such as Monte Carlo and Molecular Dynamics simulations.