Properties of the Ribose-Ring-Opened Adenic Nucleotide 2,2'[1-(9-adenyl)-1'-(tri-,diphosphoryl-oxymethyl)]-dihydroxydiethylether in Mitochondrial Adenine-Nucleotide Translocation.

(Adenine-14C) or (γ-32P)-labelled 2,2'[1-(9-adenyl)-1'-(tri-, diphosphoryl-oxymethyl)]-dihydroxydiethylether (rroANP) was obtained from AArp by cleavage of the C-2'-C-3' bond by sodium periodate oxidation and subsequent borohydride reduction. Binding of rroANP to rat liver mitochondria revealed carrier-linked (atractyloside-sensitive) and unspecific (atractyloside-insensitive) binding but no transfer across the inner mitochondrial membrane. Kinetic data indicate rroANP as a competitive inhibitor for ANP uptake with Ki = 9.3 × 10-5 M. Experimental rroANP confirmed that an intact adenine base and three anionic charges of the phosphate chain are essential for the recognition between ANP-carrier and nucleotide but insufficient for the induction of a transmembrane ANP exchange. In addition mobilisation of the carrier-nucleotide complex requires an intact ribofuranoside ring system. [ABSTRACT FROM AUTHOR]