Opposite effects of 2-aminoethanesulfonic acid (taurine) and aminomethanesulfonic acid on calcium ion uptake in rat retinal preparations.

It is well known that taurine stimulates ATP-dependent calcium ion uptake at low calcium ion concentrations. However, aminomethanesulfonic acid, the lower homologue of taurine, inhibits calcium ion uptake under the same experimental conditions. The higher homologue of taurine, 3-aminopropanesulfonic acid, has no effect on calcium ion uptake. These data demonstrate that the carbon chain length between the amino and sulfonic acid moieties is critical for the resultant effect on the calcium ion transport process.