Sulfoquinovosyl diacylglycerol

Sulfoquinovosyl diacylglycerols, abbreviated SQDG, are a class of sulfur-containing but phosphorus-free lipids (sulfolipids) found in many photosynthetic organisms.

A. Benson and coworkers discovered a new sulfur-containing lipid in plants and identified it as sulfoquinovosyl diacylglycerol (SQDG).

[2] SQDGs have been found in all photosynthetic plants, algae, cyanobacteria, purple sulfur and non-sulfur bacteria and is localised in the thylakoid membranes, being the most saturated glycolipid.

In some cases the (electrostatic) interactions may be very strong, as suggested by the inability of saturated SQDG molecules associated with purified chloroplast CF0-CF1 ATPase to exchange with other acidic lipids.

Mitochondrial coupling factor F1 is similarly protected by phospholipids and SQDGs although, in that case, both were equally effective.