Spontaneous curvature of phosphatidic acid and lysophosphatidic acid.

The formation of phosphatidic acid (PA) from lysophosphatidic acid (LPA), diacylglycerol, or phosphatidylcholine plays a key role in the regulation of intracellular membrane fission events, but the underlying molecular mechanism has not been resolved. A likely possibility is that PA affects local membrane curvature facilitating membrane bending and fission. To examine this possibility, we determined the spontaneous radius of curvature (R(0p)) of PA and LPA, carrying oleoyl fatty acids, using well-established X-ray diffraction methods.

The effects of acyl chain length and saturation of diacylglycerols and phosphatidylcholines on membrane monolayer curvature.

The second messenger, diacylglycerol (DAG), introduces negative curvature in phospholipid monolayers and strongly induces the lamellar (L(alpha)) to reverse hexagonal (H(II)) phase transition. The chain lengths and degree of unsaturation of symmetric DAGs influence this effect. Within dioleoylphosphatidylcholine (DOPC) monolayers, the apparent spontaneous radius of curvature (R(0)) of the short, saturated dicaprylglycerol (C10-DCG) itself was determined to be -13.