title: Evidence that the recently discovered high-energy nucleotide derivative, oligo(phosphoglyceroyl-ATP) forms the end chains of purinogen, a complex polymeric major storage form of adenine nucleotide and phosphate in heart.
abstract: Previous work in our laboratory has shown that free adenine nucleotides in heart, liver and kidney exchange rapidly with a major acid-insoluble species which we have characterised as oligo[3-phospho-glyceroyl-gamma- triphospho(5')adenosine(3')], abbreviated to (PG-ATP)n. This has been found in liver and in heart to be complexed to a specific 3'-phosphodiesterase which releases PG-ATP monomers and is located in mitochondrial inter-membrane space. In [14C]adenosine-perfused hearts, (PG-ATP)n has been shown to reach specific radioactivity equilibrium with free ATP within 30 min. Attempts to estimate the quantities of nucleotide in (PG-ATP)n and free nucleotides in response to a variety of stimuli using previously labelled hearts showed by contrast that the free and sequestered nucleotide pools were not at equilibrium. Re-examination of the rapidly labelled acid-insoluble species led to the recognition of radioactive inhomogeneity and of three additional nucleotide components. Perfusion of hearts with phosphate-free medium increased the proportion of 14C incorporated into the sequestered from by 70% and caused the net transfer of 0.9 mumol.g-1 of purine from free adenine nucleotides to the sequestered form. The findings point to the existence of a more complex polymer whose rapidly exchanging end chains we had previously isolated and characterised as (PG-ATP)n; we suggest the name purinogen for this polymer and show that it can contain between 25% and 55% of the tissue nucleotide pool in rat heart.
authors.affiliation: Department of Biochemistry and Molecular Biology, University College London, England.
authors.forename: B
authors.initials: B
authors.lastname: Patel
authors.forename: M
authors.initials: M
authors.lastname: Sarcina
authors.forename: J
authors.initials: J
authors.lastname: Mowbray
mesh_terms: D000227:Adenine Nucleotides / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000737:chemistry; D000818:Animals; D004734:Energy Metabolism; D005994:Glycerophosphates / Q000737:chemistry*; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D011108:Polymers; D051381:Rats
chemical_list: D000227:Adenine Nucleotides; D005994:Glycerophosphates; D011108:Polymers; C049248:phosphoglyceroyl-ATP; D000255:Adenosine Triphosphate