Dynamic conformational changes of surface membrane of true slime mold in response to chemoreception revealed by reactivity with chemical agents

Abstract

1. 1. Structural changes of the surface membrane of Physarum polycephalum were examined by labelling the membrane proteins with [ 14 C]p- chloromercuribenzoate or 125I under various conditions. 2. 2. Reception of repellents such as NaCl, CaCl 2, LaCl 3 and fructose led to an exposure of proteins on the surface of microplasmodia, while attractants such as NaH 2PO 4, c-AMP, Ca(H 2PO 4) 2 and glucose in a certain concentration range led to an embedment of the surface proteins. 3. 3. The proteins exposed on the surface of microplasmodia under the presence of chemical stimuli were released into the external medium when the microplasmodia were transferred into a solution containing no chemical stimuli.