title: Membrane structure and the tenuously maintained resistance to staining with N epsilon-dansyl-L-lysine shown by many cells.
abstract: The ability to resist staining by N epsilon-dansyl-L-lysine is tenuously maintained in the majority of live nucleated cells taken from tissues concerned with immune function. Resistance is lost under a variety of nonphysiological conditions known to, or likely to, cause protein denaturation or aggregation. In contrast to that of dansyl-gamma-aminobutyrate, the fluorescence intensity of N epsilon-dansyl-L-lysine is only weakly enhanced by native proteins. This is further reduced on denaturation or aggregation of the proteins. It is unlikely, therefore, that cellular uptake of, and staining by, N epsilon-dansyl-L-lysine is a direct consequence of membrane protein denaturation/aggregation but may result from a decrease in protein-phospholipid interactions leading to formation of phospholipid domains. Previous work has indicated that such features are stained by N epsilon-dansyl-L-lysine (Humphries, G.M.K., Lovejoy, J.P., 1983, Biophys. J. 42:307-310; Humphries, G.M.K., Lovejoy, J.R., 1983, Biochem. Biophys. Res. Commun. 111:768-774). Although it appears likely that passage through a dansyl-lysine-staining state is a common, if not universal, prelude to cell death (as monitored by uptake of trypan blue), not all cells that lose resistance to dansyl-lysine staining are moribund. Resistance to staining is also lost by macrophages on binding to solid substrates and multivalent ligands. The possible physiological significance of this is discussed.
mesh_terms: D000818:Animals; D001798:Blood Proteins; D002462:Cell Membrane; D003619:Dansyl Compounds; D005122:Exudates and Transudates / Q000166:cytology* / Q000187:drug effects; D005470:Fluorometry; D005976:Glutaral / Q000494:pharmacology; D006358:Hot Temperature; D066298:In Vitro Techniques; D008081:Liposomes; D008239:Lysine / Q000031:analogs & derivatives*; D008264:Macrophages / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D011092:Polyethylene Glycols / Q000494:pharmacology; D013154:Spleen / Q000166:cytology* / Q000187:drug effects; D013194:Staining and Labeling; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives
chemical_list: D001798:Blood Proteins; D003619:Dansyl Compounds; D008081:Liposomes; C036851:dansyllysine; C040853:dansyl-4-aminobutyric acid; D011092:Polyethylene Glycols; D005680:gamma-Aminobutyric Acid; D008239:Lysine; D005976:Glutaral