The changes in the primary structures of proteins are strongly character due to evolution process. Some changes are beneficial and remain in the process of evolution, some ones are negatively affected to properties of the protein. Neutral changes in amino acid sequences can also occur, without affecting the protein and the body as a whole. Pulmonary surfactant is a surface-active lipoprotein complex (phospho-lipoprotein) formed by type II alveolar cells. The proteins and lipids that make up the surfactant have both hydrophilic and hydrophobic regions. As a medication, pulmonary surfactant is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. The object of this study is surfactant-associated proteins. The aim of the study was to identify the relationship between the amino acid composition of the protein and its functions. The study of the structure of proteins was carried out using multiple alignment and building a phylogenetic tree. Proteins SP-A and SP-D are members of the C-type collectin family and consist of four domains: N-terminal sequence, collagen-like domain, carbohydrate recognition domain (CRD), “neck” between collagen-like and carbohydraterecognizing domains. Functionally, the most important are the C4 and CRD domains. Point mutations in these domains affect the change in the properties of proteins.
Nucleotide and amino acid sequences of pulmonary surfactant protein SP 18 and evidence for cooperation between SP 18 and SP 28-36 in surfactant lipid adsorption.
