title: Opposite diastereoselective activation of P2Y1 and P2Y11 nucleotide receptors by adenosine 5'-O-(alpha-boranotriphosphate) analogues.
abstract: OBJECTIVE
  We explored the stereoselective activation of the P2Y11 receptor, stably expressed and tagged with GFP, in 1321N1 cells, in comparison to its closest homologue, the P2Y1 receptor.
  
  
  METHODS
  The potency of several chiral ATP analogues was determined by measuring increases in intracellular calcium concentration ([Ca2+]i). In a series of ATP-alpha-B and ATP-alpha-S analogues, a non-bridging oxygen atom of Palpha was substituted by BH3 or sulphur, respectively, introducing a chiral center at Palpha. The pairs of diastereoisomers (A and B isomers) were each applied as purified compounds.
  
  
  RESULTS
  The (B) isomers (ATP-alpha-B Sp isomers and ATP-alpha-S Rp isomers) of all derivatives tested were more potent at the P2Y11 receptor than the corresponding (A) isomers (ATP-alpha-B Rp isomers and ATP-alpha-S Sp isomers) and the parent compounds. This characteristic of the P2Y11 receptor is opposite to the behaviour of the same diastereoisomers at the P2Y1 receptor, at which the (A) isomers are more active.
  
  
  CONCLUSIONS
  The distinctly opposite diastereoselective activity of ATP derivatives at the P2Y11 and the P2Y1 receptor will allow the deciphering of structural differences of the ligand recognition sites between these receptor subtypes and may aid in the development of subtype-selective agonists. Moreover, ATP-alpha-B diastereoisomers are not active at the P2Y2 receptor. Thus, they are compounds suitable for distinguishing the functional contribution of the two ATP-activated P2Y receptors, the P2Y2 and P2Y11 receptor, in physiological or pathophysiological responses of cells.
authors.affiliation: Institut für Neurobiochemie, Medizinische Fakultät, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Ecke
authors.forename: M E
authors.initials: ME
authors.lastname: Tulapurkar
authors.forename: V
authors.initials: V
authors.lastname: Nahum
authors.forename: B
authors.initials: B
authors.lastname: Fischer
authors.forename: G
authors.initials: G
authors.lastname: Reiser
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D001896:Boron Compounds / Q000737:chemistry / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects; D045744:Cell Line, Tumor; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000378:metabolism; D058472:Receptors, Purinergic P2Y1; D011993:Recombinant Fusion Proteins / Q000819:agonists / Q000378:metabolism; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014162:Transfection
chemical_list: D001896:Boron Compounds; C546382:P2RY1 protein, human; C109734:P2RY11 protein, human; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D000255:Adenosine Triphosphate