BAPTA

Chembox new
ImageFile=bapta.pngImageSize=
IUPACName=1,2-bis(o-aminophenoxy)ethane- N,N,N',N'-tetraacetic acid
OtherNames=
Section1= Chembox Identifiers
CASNo=85233-19-8
PubChem=104751
SMILES=
Section2= Chembox Properties
Formula=C₂₂H₂₄N₂O₁₀
MolarMass=476.433
Appearance=
Density=1.494 g/cm³
MeltingPt=177-179 °C
BoilingPt=
Solubility=
Section3= Chembox Hazards
MainHazards=
FlashPt=
Autoignition=

BAPTA (1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) is a calcium-specific chelator. The presence of four carboxylic acid functional groups makes possible the binding of two calcium ions. The extensive flexibility of the carboxylate ligands is critical to the coordination of calcium, or other metal ions. Recent studies have demonstrated that the BAPTA moiety actually binds to zinc ions with a substantially higher affinity than calcium. [cite journal | author=Hyrc KL, Bownik JM, and Goldberg MP | title=Ionic selectivity of low affinity ratiometric calcium indicators: mag-fura-2, fura-2FF and BTC | journal=Cell Calcium | volume=27 | issue= | pages=75–86 | year=2005 | doi=10.1054/ceca.1999.0092] Interestingly, it appears that the assumption of the chelator's calcium preference may have contributed to evidence for the role of calcium ions as causal agents in ischemia (stroke), and brain trauma. Based on this evidence, pharmacological agents "en masse" have been designed and synthesized, yet have met with little success.

There are a range of reported values for the dissociation constant of BAPTA, though 0.2 µM appears consistently [http://www.jneurosci.org/cgi/content/full/18/20/8261/T2] . The rate constant for calcium binding is 500 µM^-1 s^-1 [http://www.jneurosci.org/cgi/content/full/18/20/8261/T2] .

References

See also

* EDTA
* EGTA
* Fura-2

External links