K. Holmberg et al., Interactions between a lipase and charged surfactants - a comparison between bulk and interfaces, ADV COLL IN, 88(1-2), 2000, pp. 223-241
The interaction between a charged surfactant and a lipase has been investig
ated by several methods. Interactions in aqueous bulk phase was studied by
NMR and by microcalorimetry. Surface tension and neutron reflectivity were
used for studies at the air-water interface. Interactions at the interface
between a hydrophobic solid surface and water was investigated by ellipsome
try. The results obtained are as follows. The cationic surfactant, tetradec
yltrimethylammonium bromide (iodide in the NMR experiments), showed strong
interaction at the air-water and the hydrophobic solid-water interfaces but
no clear indication of an interaction in bulk phase was seen. The anionic
surfactant showed no interaction with the lipase neither at the interfaces,
nor in bulk. The difference in behavior of the system cationic surfactant-
lipase in bulk and at the interfaces may be due to the change in enzyme con
formation that is known to occur at interfaces between water and an apolar
phase. (C) 2000 Elsevier Science B.V. All rights reserved.