1: Biochim Biophys Acta  1992 Feb 17;1104(1):9-14 

Fluorescence quenching measurements of the membrane bound lipid haptens with
different length spacers.

Kimura K, Arata Y, Yasuda T, Kinosita K Jr, Nakanishi M.

Faculty of Pharmaceutical Sciences, Nagoya City University, Japan.

Dansyl lipid haptens with three different length (short, intermediate and long)
spacers have been incorporated into DMPC or DPPC liposomes. Anti-DNS-IgG bound
most efficiently to these liposomes containing lipid haptens with an
intermediate length spacer, although the binding efficiency became more
increased when liposomes were made of a mixture of phospholipid (DMPC or DPPC)
and cholesterol. To explain these results we have measured the accessibility of
dansyl lipid haptens in liposomal membranes by the fluorescence quenching
method. It was found that the dansyl haptens located on the surfaces of DMPC (or
DPPC) membranes and fluorescence quenchers (iodide ions) possessed almost
similar accessibility for the dansyl haptens with different length spacers.
However, in the DMPC (or DPPC) membranes with 50% cholesterol, a part of the
dansyl haptens became buried into the interior of the liposomal membranes
depending on the length of the spacer and another part removed into the aqueous
solution with greater affinity for antibody. These results were explained well
by our recent model for antibody binding to the membrane-bound lipid haptens.

PMID: 1550857 [PubMed - indexed for MEDLINE]