Influence of encapsulated enzyme on the surface properties of freeze-dried liposomes in trehalose

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 17; no. 2; pp. 103 - 109
• Main Author: Bakás, Laura
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-02-2000
• Subjects: Enzyme encapsulation; Freeze-drying; Liposomes; Membrane surface properties; ANS, 1,8-anilino-naphatalene sulphonate; MC540, Merocyanine 540; Membrane surface properties; PE,phosphatidylethanolamine; MLV, multilamellar liposomes; Liposomes; Enzyme encapsulation; FDT-liposomes, freeze-dried liposomes in trehalose; Freeze-drying; lysoPC, lysophosphatidylcholine; PCegg, egg phosphatidylcholine; SA, estearylamine
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/S0927-7765(99)00106-X

The interfacial properties of liposomes in which a soluble protease from
Mucor meihie was encapsulated and subjected to freeze-drying procedure in the presence of trehalose, have been studied. Enzyme encapsulation in liposomes subjected to freeze-drying produces changes in the membrane interfacial properties as a consequence of penetration of some of the protein hydrophobic portion into the lipid bilayer. This membrane perturbation can be explained when considering that the presence of trehalose during the freeze-drying process brings about membrane hydrophobic defects where the protein can be accommodated without inducing any additional disorder. These interfacial changes in the membrane were detected by a decreased partition of Merocyanine 540, loss in the lytic effect of lysoderivatives and an increase in ANS binding sites in comparison to freeze-dried liposomes in the absence of protease. This information can be useful to modify the enzyme release of liposomes in a controlled way as a function of the interacting molecules present in the outside environment.