title: Effect of serum, cholesterol and low density lipoprotein on the functionality and structure of lung surfactant films.
abstract: Lung surfactant is a complex mixture of lipid and protein, responsible for alveolar stability, becomes dysfunctional due to alteration of its structure and function by leaked serum materials in disease. Serum proteins, cholesterol and low density lipoprotein (LDL) were studied with bovine lipid extract surfactant (BLES) using Langmuir films, and bilayer dispersions using Raman spectroscopy. While small amount of cholesterol (10 wt%) and LDL did not significantly affect the adsorption and surface tension lowering properties of BLES. However serum lipids, whole serum as well as higher amounts of cholesterol, and LDL dramatically altered the surface properties of BLES films, as well as gel-fluid structures formed in such films observed using atomic force microscopy (AFM). Raman-spectroscopic studies revealed that serum proteins, LDL and excess cholesterol had fluidizing effects on BLES bilayers dispersion, monitored from the changes in hydrocarbon vibrational modes during gel-fluid thermal phase transitions. This study clearly suggests that patho-physiological amounts of serum lipids (and not proteins) significantly alter the molecular arrangement of surfactant in films and bilayers, and can be used to model lung disease.
authors.affiliation: Department of Chemistry, University of North Bengal.
authors.forename: Prasant
authors.initials: P
authors.lastname: Nahak
authors.forename: Kaushik
authors.initials: K
authors.lastname: Nag
authors.forename: Ashley
authors.initials: A
authors.lastname: Hillier
authors.forename: Ravi
authors.initials: R
authors.lastname: Devraj
authors.forename: David W
authors.initials: DW
authors.lastname: Thompson
authors.forename: Kausik
authors.initials: K
authors.lastname: Manna
authors.forename: Kimiko
authors.initials: K
authors.lastname: Makino
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ohshima
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Nakahara
authors.forename: Osamu
authors.initials: O
authors.lastname: Shibata
authors.forename: Amiya Kumar
authors.initials: AK
authors.lastname: Panda
mesh_terms: D000327:Adsorption; D001798:Blood Proteins / Q000032:analysis; D002784:Cholesterol / Q000032:analysis; D008051:Lipid Bilayers / Q000032:analysis; D008077:Lipoproteins, LDL / Q000032:analysis; D008560:Membrane Fluidity; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D044367:Phase Transition; D011663:Pulmonary Surfactants / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D001798:Blood Proteins; D008051:Lipid Bilayers; D008077:Lipoproteins, LDL; D011663:Pulmonary Surfactants; D002784:Cholesterol