What is the charge of phosphatidylglycerol at pH 7?

Phosphatidylglycerol, a phospholipid that contains a glycerol backbone, two fatty acid tails, and a phosphate group, carries a negative charge at physiological pH, which is approximately 7. At this pH, the phosphate group of phosphatidylglycerol is deprotonated and exists as negatively charged due to the ionization of its acidic hydrogen.

The carboxyl group in the glycerol portion may also be considered; however, it does not significantly contribute to the charge at pH 7. The overall structure results in a net charge of -1. This property influences the behavior of phosphatidylglycerol within biological membranes, as negatively charged lipids play key roles in membrane dynamics and interactions with proteins and ions.

In summary, at pH 7, phosphatidylglycerol predominantly carries a single negative charge.