High-Yield Purification of Lung Surfactant Proteins SP-B and SP-C and the Effects on Surface Activity

• DOI: 10.1006/prep.2001.1492
• Publication Date: 2002-09-18T20:38:41Z
• Authors: John E. Baatz; Yong Zou; J.Thomas Cox; Zhengdong Wang; Robert H. Notter
• Keywords: Chromatography; 0303 health sciences; 03 medical and health sciences; Sequence Analysis, Protein; Proteolipids; Solvents; Animals; Surface Tension; Cattle; Pulmonary Surfactants; Adsorption; Phospholipids

Several protocols for purification of milligram quantities of lung surfactant proteins (SP)-B and SP-C were studied for separation efficiency and surface activity of the isolated proteins recombined with synthetic phospholipids (SPL). SP-B and SP-C were obtained from calf lung surfactant extract by C8 chromatography with isocratic elution by either of three solvent systems: 7:1:0.4 MeOH/CHCl(3)/5% 0.1 M HCl (solvent A), 7:1 MeOH/CHCl(3)+ 0.1% TFA (solvent B), and 7:1:0.4 MeOH/CHCl(3)/H(2)O + 0.1% TFA (solvent C). Solvents A and C yielded pure apoprotein in a single pass, with estimated total protein recoveries of >85 and >90%, respectively. Solvent B was less effective in purifying SP-B and SP-C, had a lower recovery efficiency, and gave isolates with less surface activity. Mixtures of SPL plus SP-B eluted with solvents A and C adsorbed to equilibrium surface tensions of 21-22 mN/m and reached minimum surface tensions <1 mN/m during dynamic cycling. Mixtures of SPL with SP-C obtained with solvents A and C had equilibrium surface tensions of 26-27 mN/m and minimum dynamic values of 2-7 mN/m. The ability to obtain milligrams of virtually lipid-free SP-B and SP-C in a single column pass will facilitate research on their biological, structural, and biophysical properties.