Regioselective Approach to Phosphatidylinositol 3,5-Bisphosphates: Syntheses of the Native Phospholipid and Biotinylated Short-Chain Derivative

A selective bis-silylation of 1D-O-TBDPS-myo-inositol leads to a 1,3,5-trisubstituted inositol, which can be advanced to the headgroup of phosphatidylinositol-3,5-bisphosphate [PI(3,5)P-2]. A mild, regioselective method for construction of the diacylglycerol moiety containing differing fatty acid chains, including the naturally occurring lipids, was developed. Their union in the synthesis of the cell-signaling molecule PI(3,5)P-2 containing the RP-I-stearoyl and sn-2-arachidonoyl groups is described. The methodology was also used to generate dioctanoyl-PI(3,5)P-2 and a previously unreported biotin-PI(3,5)P-2 conjugate, which was coupled to neutravidin beads and used to pull down PI(3.5)P-2-binding proteins from the cytosolic extract of adrenal neurosecretory cells. We report the specific pull-down of the PI(3,5)P-2-binding protein svp1p, a known PI(3,5)P-2 effector involved in membrane t To flick