Selective transport of nucleotides mediated by functionalized porphyrin

Abstract

Nucleotide transport through liquid membranes using a zinc(II)-porphyrin having two lipophilic ammonium side chains (1·Zn) was investigated. Two characteristic features of the present transport system became apparent, i.e. (1) the rate of transport of AMP is much faster than those of other nucleotide, and (2) 1·Zn is more effective than the corresponding free porphyrin for any nucleotide transport. The selectivity toward AMP remains even under a competitive condition where AMP, GMP, CMP and UMP coexist. The steady state concentration of AMP during the transport is found to be practically same with a maximum concentration observed in a extraction experiment using a simple two phase system. The result strongly suggests that the rate determining step of the present transport system is the substrate releasing step from the membrane CHCl₃ phase to the receiver aqueous one.