TY - JOUR
T1 - Structural changes in films of pulmonary surfactant induced by surfactant vesicles
AU - Andreev, Konstantin
AU - Martynowycz, Michael W.
AU - Kuzmenko, Ivan
AU - Bu, Wei
AU - Hall, Stephen B.
AU - Gidalevitz, David
N1 - Funding Information:
The authors thank Dr. Edmund Egan (ONY, Inc., Amherst, NY) for the gift of CLSE. This research was supported by funds from the National Institutes of Health (HL130130 and 136734). This study used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357. NSF’s ChemMatCARS Sector 15 (beamline ID-15-C) is supported by the Divisions of Chemistry (CHE) and Materials Research (DMR), National Science Foundation, under grant number NSF/CHE-1834750.
Publisher Copyright:
© XXXX American Chemical Society
PY - 2020
Y1 - 2020
N2 - When compressed by the shrinking alveolar surface area during exhalation, films of pulmonary surfactant in situ reduce surface tension to levels at which surfactant monolayers collapse from the surface in vitro. Vesicles of pulmonary surfactant added below these monolayers slow collapse. X-ray scattering here determined the structural changes induced by the added vesicles. Grazing incidence X-ray diffraction on monolayers of extracted calf surfactant detected an ordered phase. Mixtures of dipalmitoyl phosphatidylcholine and cholesterol, but not the phospholipid alone, mimic that structure. At concentrations that stabilize the monolayers, vesicles in the subphase had no effect on the unit cell, and X-ray reflection showed that the film remained monomolecular. The added vesicles, however, produced a concentration-dependent increase in the diffracted intensity. These results suggest that the enhanced resistance to collapse results from enlargement by the additional material of the ordered phase.
AB - When compressed by the shrinking alveolar surface area during exhalation, films of pulmonary surfactant in situ reduce surface tension to levels at which surfactant monolayers collapse from the surface in vitro. Vesicles of pulmonary surfactant added below these monolayers slow collapse. X-ray scattering here determined the structural changes induced by the added vesicles. Grazing incidence X-ray diffraction on monolayers of extracted calf surfactant detected an ordered phase. Mixtures of dipalmitoyl phosphatidylcholine and cholesterol, but not the phospholipid alone, mimic that structure. At concentrations that stabilize the monolayers, vesicles in the subphase had no effect on the unit cell, and X-ray reflection showed that the film remained monomolecular. The added vesicles, however, produced a concentration-dependent increase in the diffracted intensity. These results suggest that the enhanced resistance to collapse results from enlargement by the additional material of the ordered phase.
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U2 - 10.1021/acs.langmuir.0c01813
DO - 10.1021/acs.langmuir.0c01813
M3 - Article
C2 - 33080138
AN - SCOPUS:85096010457
JO - Langmuir
JF - Langmuir
SN - 0743-7463
ER -