title: Attachment of water-soluble proteins to the surface of (magnetizable) phospholipid colloids via NeutrAvidin-derivatized phospholipids.
abstract: The present work describes the incorporation of a functionalized phospholipid derivative into the phospholipid bilayer of both classical small unilamellar vesicles and recently developed magnetoliposomes, resulting in unique biocolloid structures onto which peripheral water-soluble enzymes can be immobilized on the surfaces. In the first part of this work, a synthesis protocol is outlined for a universal membrane anchor for water-soluble proteins. Dioleoylphosphatidylethanolamine-N-dodecanyl was used as the starting lipid molecule. After activation of the terminal -COOH group, alpha,omega-diamino-poly(ethylene glycol), used as a hydrophilic, flexible spacer arm, was coupled covalently. Subsequently, NeutrAvidin was bound, after blocking the free -NH(2) groups with citraconic anhydride. In the second part, the resulting lipid-NeutrAvidin derivative was incorporated into small unilamellar vesicles comprised of dimyristoylphosphatidylglycerol. FPLC with Superdex 200 as the column matrix clearly showed that biotinylated alkaline phosphatase, which served as a representative model of water-soluble proteins, was attached to the vesicles. Furthermore, magnetoliposomes, constructed of the same type of phospholipid molecules, were presented as interesting colloids to assess the degree of enzyme immobilization in a rapid and elegant manner. Potential applications that can emerge from this study are briefly discussed.
authors.affiliation: Interdisciplinair Research Centrum, Katholieke Universiteit Leuven-Campus Kortrijk, Kortrijk, B-8500, Belgium. Marcel.Decuyper@kulak.ac.be
authors.forename: Marcel
authors.initials: M
authors.lastname: De Cuyper
authors.forename: Michael
authors.initials: M
authors.lastname: Hodenius
authors.forename: Zulmira G M
authors.initials: ZG
authors.lastname: Lacava
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Azevedo
authors.forename: Maria de Fátima
authors.initials: Mde F
authors.lastname: da Silva
authors.forename: Paulo Cesar
authors.initials: PC
authors.lastname: Morais
authors.forename: Maria Helena Andrade
authors.initials: MH
authors.lastname: Santana
mesh_terms: D001360:Avidin / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D008280:Magnetics; D015394:Molecular Structure; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D003102:Colloids; D004800:Enzymes, Immobilized; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D011506:Proteins; C093483:neutravidin; C403812:phosphatidylethylene glycol; D014867:Water; D001360:Avidin; C094877:dioleoyl phosphatidylethanolamine