Rv. Diemel et al., Functional tests for the characterization of surfactant protein B (SP-B) and a fluorescent SP-B analog, ARCH BIOCH, 385(2), 2001, pp. 338-347
Surfactant protein B (SP-B) enhances lipid insertion into the alveolar air/
liquid interface upon inhalation. The aim of this study was (i) to apply a
palette of tests for a detailed biochemical and biophysical characterizatio
n of SP-B and (ii) to use these tests to compare native SP-B with a fluores
cent (Bodipy) SP-B analog. The method of labeling was fast and resulted in
a covalent fluorophore-protein bond. The ability of both proteins to spread
a surfactant film on top of a buffer surface was determined in a spreading
tray using the Wilhelmy plate technique to allow detection of alterations
in surface tension and calculation of spreading velocities. In a captive bu
bble surfactometer surface tensions of spread films were measured, Similar
biophysical properties were found for both native and Bodipy-labeled SP-B.
It is concluded that the combination of tests used allows detection of smal
l differences in structure and activity between the two proteins. (C) 2001
Academic Press.