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Article: Isothermal titration calorimetry reveals a zinc ion as an atomic switch in the diadenosine polyphosphates

TitleIsothermal titration calorimetry reveals a zinc ion as an atomic switch in the diadenosine polyphosphates
Authors
Issue Date2002
PublisherAmerican Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jbc.org/
Citation
Journal Of Biological Chemistry, 2002, v. 277 n. 5, p. 3073-3078 How to Cite?
AbstractDiadenosine polyphosphates (diadenosine 5′,5‴-P1,Pn-polyphosphate (ApnA)) are 5′-5‴-phosphate-bridged dinucleosides that have been proposed to act as signaling molecules in a variety of biological systems. Isothermal titration calorimetry was used to measure the affinities of a variety of metal cations for ATP, diadenosine 5′,5‴,P1,P3-triphosphate (Ap3A), diadenosine 5′,5′-P1,P4-tetraphosphate (Ap4A), and diadenosine 5′,5‴-P1,P5-pentaphosphate (Ap5A). The binding of Mg2+, Ca2+, and Mn2+ to ATP is shown to take place with the β, γ-phosphates (primary site) and be endothermic in character. The binding of Ni2+, Cd2+, and Zn2+ to ATP is found to take place at both the primary site and at a secondary site identified as N-7 of the adenine ring. Binding to this second site is exothermic in character. Generally, the binding of metal cations to diadenosine polyphosphates involves a similar primary site to ATP. No exothermic binding events are identified. Critically, the binding of Zn2+ to diadenosine polyphosphates proves to be exceptional. This appears to involve a very high affinity association involving the N-7 atoms of both adenine rings in each ApnA, as well as the more usual endothermic association with the phosphate chain. The high affinity association is also endothermic in character. A combination of NMR and CD evidence is provided in support of the calorimetry data demonstrating chemical shift changes and base stacking disruptions entirely consistent with N-7 bridging interactions. N-7 bridging interactions are entirely reversible, as demonstrated by EDTA titration. Considering the effects of Zn2+ on a wide variety of dinucleoside polyphosphate-metabolizing enzymes, we examine the possibility of Zn2+ acting as an atomic switch to control the biological function of the diadenosine polyphosphates.
Persistent Identifierhttp://hdl.handle.net/10722/68042
ISSN
2015 Impact Factor: 4.258
2015 SCImago Journal Rankings: 3.151
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorTanner, JAen_HK
dc.contributor.authorAbowath, Aen_HK
dc.contributor.authorMiller, ADen_HK
dc.date.accessioned2010-09-06T06:00:47Z-
dc.date.available2010-09-06T06:00:47Z-
dc.date.issued2002en_HK
dc.identifier.citationJournal Of Biological Chemistry, 2002, v. 277 n. 5, p. 3073-3078en_HK
dc.identifier.issn0021-9258en_HK
dc.identifier.urihttp://hdl.handle.net/10722/68042-
dc.description.abstractDiadenosine polyphosphates (diadenosine 5′,5‴-P1,Pn-polyphosphate (ApnA)) are 5′-5‴-phosphate-bridged dinucleosides that have been proposed to act as signaling molecules in a variety of biological systems. Isothermal titration calorimetry was used to measure the affinities of a variety of metal cations for ATP, diadenosine 5′,5‴,P1,P3-triphosphate (Ap3A), diadenosine 5′,5′-P1,P4-tetraphosphate (Ap4A), and diadenosine 5′,5‴-P1,P5-pentaphosphate (Ap5A). The binding of Mg2+, Ca2+, and Mn2+ to ATP is shown to take place with the β, γ-phosphates (primary site) and be endothermic in character. The binding of Ni2+, Cd2+, and Zn2+ to ATP is found to take place at both the primary site and at a secondary site identified as N-7 of the adenine ring. Binding to this second site is exothermic in character. Generally, the binding of metal cations to diadenosine polyphosphates involves a similar primary site to ATP. No exothermic binding events are identified. Critically, the binding of Zn2+ to diadenosine polyphosphates proves to be exceptional. This appears to involve a very high affinity association involving the N-7 atoms of both adenine rings in each ApnA, as well as the more usual endothermic association with the phosphate chain. The high affinity association is also endothermic in character. A combination of NMR and CD evidence is provided in support of the calorimetry data demonstrating chemical shift changes and base stacking disruptions entirely consistent with N-7 bridging interactions. N-7 bridging interactions are entirely reversible, as demonstrated by EDTA titration. Considering the effects of Zn2+ on a wide variety of dinucleoside polyphosphate-metabolizing enzymes, we examine the possibility of Zn2+ acting as an atomic switch to control the biological function of the diadenosine polyphosphates.en_HK
dc.languageengen_HK
dc.publisherAmerican Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jbc.org/en_HK
dc.relation.ispartofJournal of Biological Chemistryen_HK
dc.rightsJournal of Biological Chemistry. Copyright © American Society for Biochemistry and Molecular Biology, Inc.en_HK
dc.subject.meshAdenosine Triphosphate - chemistryen_HK
dc.subject.meshBinding Sitesen_HK
dc.subject.meshCalorimetry - methodsen_HK
dc.subject.meshCations, Divalent - chemistryen_HK
dc.subject.meshCircular Dichroismen_HK
dc.subject.meshDinucleoside Phosphates - chemistryen_HK
dc.subject.meshManganese - chemistryen_HK
dc.subject.meshMolecular Conformationen_HK
dc.subject.meshZinc - chemistryen_HK
dc.titleIsothermal titration calorimetry reveals a zinc ion as an atomic switch in the diadenosine polyphosphatesen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0021-9258&volume=277&spage=3073&epage=3078&date=2002&atitle=Isothermal+titration+calorimetry+reveals+a+zinc+ion+as+an+atomic+switch+in+the+diadenosine+polyphosphatesen_HK
dc.identifier.emailTanner, JA:jatanner@hku.hken_HK
dc.identifier.authorityTanner, JA=rp00495en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1074/jbc.M106588200en_HK
dc.identifier.pmid11604396en_HK
dc.identifier.scopuseid_2-s2.0-0036479222en_HK
dc.identifier.hkuros84811en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-0036479222&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume277en_HK
dc.identifier.issue5en_HK
dc.identifier.spage3073en_HK
dc.identifier.epage3078en_HK
dc.identifier.isiWOS:000173688000004-
dc.publisher.placeUnited Statesen_HK
dc.identifier.scopusauthoridTanner, JA=35513993000en_HK
dc.identifier.scopusauthoridAbowath, A=6504704195en_HK
dc.identifier.scopusauthoridMiller, AD=7406230808en_HK

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