Effects of aminocycloalkanesulfonic acid analogs of taurine on ATP-dependent calcium ion uptake and protein phosphorylation.

A cyclopentane analog of taurine [(+/-)cis-2-aminocyclopentanesulfonic acid] (CAPS) was synthesized, and its effects on ATP-dependent calcium ion uptake and protein phosphorylation in rat retina were investigated along with other cyclic analogs of taurine, (+/-)trans-2-Aminocyclopentanesulfonic acid (TAPS) is the most potent aminocycloalkanesulfonic acid inhibitor of ATP-dependent calcium ion uptake in retinal homogenates [S.M. Leibowitz, J.B. Lombardini and P.S. Salva, Biochem. Pharmac. 36, 2109 (1987)], eliciting its effects in the micromolar range (I50 = 39 +/- 5 microM). CAPS was found to be a less potent aminocycloalkanesulfonic acid inhibitor (I50 = 1780 +/- 400 microM) of ATP-dependent calcium ion uptake in retinal homogenates. Taurine inhibited phosphate incorporation into rat retinal proteins, whereas TAPS, TAHS and CAPS stimulated incorporation.