Properties of the ribose-ring-opened adenine nucleotide, 2,2'(1-(9-adenyl)-1'-(tri-,diphosphoryl-oxymethyl))-dihydroxydiethylether in mitochondrial adenine-nucleotide translocation.

(Adenine-14C) or (gamma-32P)-labelled 2,2'1-(9-adenyl)-1'-(tri-, diphosphoryl-oxymethyl]-dihydroxydiethylether (rroANP) was obtained from ANP 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 X 10(-5) M. Experimental rroANP confirmed that an intact adenine base and three anio.nic 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.