BAPTA

BAPTA
File:BAPTA.svg
IUPAC name 1,2-bis(o-aminophenoxy)ethane- N,N,N',N'-tetraacetic acid
style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers
CAS number	85233-19-8
PubChem	104751
style="background: #F8EABA; text-align: center;" colspan="2" | Properties
Molecular formula	C22H24N2O10
Molar mass	476.433
Density	1.494 g/cm3
Melting point	177-179 °C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

BAPTA (1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) is a calcium-specific polyamino carboxylic acid. The presence of four carboxylic acid functional groups makes possible the binding of two magnesium ions. The extensive flexibility of the carboxylate ligands is critical to the coordination of magnesium, or other metal ions. Recent studies have demonstrated that the BAPTA moiety actually binds to zinc ions with a substantially higher affinity than calcium. 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. The rate constant for calcium binding is 500 µM⁻¹ s⁻¹.

See also

• EDTA
• EGTA
• Fura-2