%0 Journal Article %A JOSÉ GONZÁLEZ RODRÍGUEZ %A JOSÉ L. LA TORRE %A EDUARDO DE ROBERTIS %T The Interaction between Atropine Sulfate and a Proteolipid from Cerebral Cortex Studied by Polarization of Fluorescence %D 1970 %J Molecular Pharmacology %P 122-127 %V 6 %N 2 %X Ultraviolet absorption and fluorescence spectra were recorded from a special proteolipid isolated from the cerebral cortex. This proteolipid has a high binding affinity for various drugs and, when dissolved in chloroform-methanol (4:1 by volume), has a sharp absorption band at 240 mµ and a weaker one at 278-280 mµ. Upon activation at 330 mµ the fluorescence emission is maximal at 380 mµ. The probable reasons for these spectroscopic properties are discussed. Under the action of increasing concentrations of atropine sulfate there is an increase in polarization of proteolipid protein fluorescence, which follows a sigmoid curve with a Hill number of 3.9. This effect of atropine sulfate can be blocked by acetylcholine and homatropine bromide. These results are discussed in relation to previously reported changes in light scattering. These observations suggest that, under the influence of certain drugs, this receptor proteolipid may undergo molecular aggregation with a high degree of cooperativity. ACKNOWLEDGMENT The authors are indebted to Dr. David N. Teller for critically reading the revised manuscript. %U https://molpharm.aspetjournals.org/content/molpharm/6/2/122.full.pdf