Methyl-beta-cyclodextrin treatment affects the thermotropic behaviour of membranes and detergent-resistant membrane fractions of cultured A431 cells.
Membranes and detergent-resistant membrane fractions isolated from human epidermoid carcinoma A431 cells after treatment with methyl-beta-cyclodextrin, a compound commonly used in pharmaceutical applications and in manipulation of membrane cholesterol content, display thermotropic transitions at about 15 degrees C and above 37 degrees C, respectively, when analyzed by differential scanning calorimetry. The transitions, absent in untreated cells, were reversible upon cycling through heating and cooling scans, and attributable to lipid components of the membranes, possibly sphingolipids. These results suggest that, after treatment with methyl-beta-cyclodextrin, membranes may show thermotropic transitions, an unusual feature for cellular bilayers, which is likely to influence biological functions.
Masserini
Massimo
M
Department of Experimental, Environmental Medicine and Biotechnology, University of Milano-Bicocca, via Cadore 48, 20052 Monza, Italy. massimo.masserini@unimib.it
Pitto
Marina
M
Raimondo
Francesca
F
Cazzaniga
Emanuela
E
Sesana
Silvia
S
Bellini
Tiziana
T
D002152:Calorimetry, Differential Scanning / Q000379:methods; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002458:Cell Fractionation / Q000379:methods*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D006801:Humans; D008563:Membrane Lipids / Q000378:metabolism; D044367:Phase Transition / Q000187:drug effects; D013696:Temperature; D047392:beta-Cyclodextrins / Q000494:pharmacology*
D003902:Detergents; D008563:Membrane Lipids; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin