Mechanism of calcium ion induced multilamellar vesicle DNA interaction

Mozafari M., Hasirci V.

JOURNAL OF MICROENCAPSULATION, vol.15, no.1, pp.55-65, 1998 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 15 Issue: 1
  • Publication Date: 1998
  • Doi Number: 10.3109/02652049809006835
  • Journal Name: JOURNAL OF MICROENCAPSULATION
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.55-65
  • Keywords: anionic liposome, DNA, fusion, gene transfer, fusion mechanism, vesicle, multilamellar, REVERSE-PHASE EVAPORATION, PH-SENSITIVE LIPOSOMES, DIRECT GENE-TRANSFER, PHOSPHOLIPID-VESICLES, CATIONIC LIPOSOMES, MEMBRANE-FUSION, PHOSPHATIDYLSERINE VESICLES, DRUG-DELIVERY, CHOLESTEROL, AGGREGATION
  • Middle East Technical University Affiliated: Yes

Abstract

The effect of Ca2+ on the DNA interaction with anionic and neutral multilamellar vesicles (MLV) has been investigated. DNA from wheat (Triticum aestivum L. Gerek) was introduced to a suspension of MLV, composed of phosphatidylcholine (PC): dicetylphosphate (DCP):cholesterol (CHOL) at different molar ratios, to which Ca2+ (5-75 mM) was subsequently added. Indication of aggregation and/or fusion was obtained via light-scattering examination following the addition of Ca2+ and DNA to the MLV medium. Using a UV spectrophotometric assay, it was observed that although DNA alone has no effect on negatively charged MLV, it enhances liposomal interaction in the presence of calcium ions. The minimal Ca2+ concentration required to promote the interaction was detected to be 10 mM, and the highest level of interaction was observed at 75 mM. The aggregation/fusion of vesicles was detected for uncharged MLV (with no DCP in their structure), as well as for the anionic ones containing c. 10% CHOL, but not for anionic MLV containing 40% CHOL. This is explained in terms of cholesterol decreasing the membrane fluidity (above the Tc of components) as a result of which more rigid vesicles become less prone to aggregation/fusion interactions.