Lung surfactant: a biotechnological challenge.

The genes for all three of the bona fide surfactant associated proteins have been cloned, allowing their production by recombinant DNA technology. In addition, improved protocols for the isolation of the natural surfactant proteins (NSP) made them available in larger quantities. Whereas, the NSP are often mixtures of allelic variants or functional isomers from gene families, the recombinant proteins (RSP) are obtained as single pure protein species. Antibodies directed against the N/RSP in combination with DNA probes have allowed new approaches to analyze the formation, location, transport, structure and functional capacities of these molecules as well as their interactions with one another and the phospholipids.