MOLECULAR STRUCTURE IN PHOSPHOLIPID ESSENTIAL TO ACTIVATE (NA+-K+-MG2+)-DEPENDENT ATPASE AND (K+-MG2+)-DEPENDENT PHOSPHATASE OF BOVINE CEREBRAL CORTEX

1. 1. The effect of mono- and dialkyl phsphates and related compounds were studied on (Na+-K+-Mg2+)-activated ATPase and (K+-Mg2+)-activated phosphatase prepared from bovine cerebral cortex by deoxycholate treatment. 2. 2. The ATPase was activated by either mono- or dialkyl phosphate. When both alkyl phospates possessed ten carbon atoms in a single alkyl residue, the activation effects were highest and comparable to those of natural phospholipids. Dodecyl sulfate (in narrow ranges of concentration), long-chain fatty acids, and alcohols were slightly effective. Alkyl amines were ineffective. 3. 3. The p-nitrophenyl phosphatase was stimulated by dialkyl phosphates only. Didecyl phosphate was again most active and the degree of its stimulation was the same as that of natural phospholipids. Monoalkyl phosphates, dodecyl sulfates long-chain fatty acids, alcohols and alkyl amines were all generally inhibitory. 4. 4. It is suggested that the essential structures needed for activation are a phosphate plus one or two fatty acyl residues for the ATPase and a phosphate plus two acyl residues for the p-nitrophenyl phosphatase. © 1969.