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Incorporation of hormone‐sensitive lipase into phosphatidylcholine vesicles
Author(s) -
Holm Cecilia,
Fredrikson Gudrun,
Sundler Roger,
Belfrage Per
Publication year - 1990
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02544384
Subject(s) - vesicle , phosphatidylcholine , lipase , chemistry , liposome , chromatography , phospholipid , chaps , amphiphile , sonication , biochemistry , enzyme , membrane , organic chemistry , polymer , copolymer
Enzymatically active, detergent‐solubilized purified hormone‐sensitive lipase (HSL) was incorporated into phosphatidylcholine (PC) vesicles, using a detergent‐dialysis procedure with small PC vesicles, obtained by sonication, as phospholipid source and CHAPS, a zwitterionic bile‐salt derivative, as detergent. Association of enzyme protein with the PC vesicles was verified by floatation in a discontinuous dextran gradient and by gel chromatography. An average of 35% of added HSL was incorporated into the vesicles. The vesicles were shown, by quasi‐elastic light scattering and electron microscopy, to have a diameter of approximately 160 nm. The vesicleassociated HSL could be phosphorylated by cyclic AMP‐dependent protein kinase. The vesicles were stable, both with regard to enzyme activity and size, for at least 4 days when stored at 4°C. The preparation of detergent‐free, vesicle‐associated and stable HSL provides new possibilities to study some of its properties, and supports and extends the previous report (Holm, C., Fredrikson, G., and Belfrage, P., J. Biol. Chem. 261 , 15659–15661, 1986) which demonstrated the amphiphilic character of HSL.