Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9102950 | Experimental and Molecular Pathology | 2005 | 7 Pages |
Abstract
When spread at the air-water interface, monophosphoryl lipid A (MPLA) forms stable insoluble monolayers that collapse at â¼55 dyn/cm. At collapse, the exclusion area of each molecule is â¼119 Ã
2, consistent with the cross-sectional area of the lipid's 6 acyl chains. The nominal thickness of such films is â¼22 Ã
, determined, presumably, by the length of the acyl chains. For biological modeling of MPLA films, a system was developed in which monolayers of the lipid are supported by monodisperse hydrophobic beads of microscopic dimensions. Beads coated with MPLA monolayers within which the nominal area of each molecule is approximately equivalent to the “take-off” area of the lipid at the air-water interface, 280 Ã
2, are mitogenic for spleen cells. Given the natural occurrence of lipid A in the bacterial cell wall as well as the inherent stability of lipid A films, it seems reasonable to assume that at least some of the biological activities attributed to the lipid derive from its presentation/operation at an interface, i.e., on a surface. We propose beads coated with adsorbed films of lipid A will prove useful tools for modeling the activities of the lipid both in vitro and in vivo, and for elucidating the surface dependency and structural requirements of those activities.
Keywords
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Clinical Biochemistry
Authors
Gregory S. Retzinger, Kuni Takayama,