2026-08-17T10:04:41Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/184182023-08-11T01:39:46Zcom_20.500.14352_14col_20.500.14352_15

Roldán López, Nuria Pérez-Gil, Jesús Morrow, Michael R. García Álvarez, Begoña 2023-06-17T22:21:40Z 2023-06-17T22:21:40Z 2017-08-22 0006-3495, ESSN: 1542-0086 10.1016/j.bpj.2017.06.059 https://hdl.handle.net/20.500.14352/18418 http://www.cell.com/biophysj/fulltext/S0006-3495(17)30743-9 Lung surfactant (LS) is an essential system supporting the respiratory function. Cholesterol can be deleterious for LS function, a condition that is reversed by the presence of the lipopeptide SP-C. In this work, the structure of LS-mimicking membranes has been analyzed under the combined effect of SP-C and cholesterol by deuterium NMR and phosphorus NMR and by electron spin resonance. Our results show that SP-C induces phase segregation at 37ºC, resulting in an ordered phase with spectral features resembling an interdigitated state enriched in dipalmitoylphosphatidylcholine, a liquid-crystalline bilayer phase, and an extremely mobile phase consistent with small vesicles or micelles. In the presence of cholesterol, POPC and POPG motion seem to be more hindered by SP-C than dipalmitoylphosphatidylcholine. The use of deuterated cholesterol did not show signs of specific interactions that could be attributed to SP-C or to the other hydrophobic surfactant protein SP-B. Palmitoylation of SP-C had an indirect effect on the extent of protein-lipid perturbations by stabilizing SP-C structure, and seemed to be important to maximize differences among the lipids participating in each phase. These results shed some light on how SP-C-induced lipid perturbations can alter membrane structure to sustain LS functionality at the air-liquid interface. eng restricted access Divide & Conquer: surfactant protein SP-C and cholesterol modulate phase segregation in lung surfactant journal article