957. BAPTA

Nomenclature

CAS number: 85233-19-8
N,N′-[1,2-Ethanediylbis(oxy-2,1-phenylene)]bis[N-(carboxymethyl)glycine]; 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid.
C22H24N2O10; mol wt 476.43.
C 55.46%, H 5.08%, N 5.88%, O 33.58%.

Description and references

Calcium (Ca2+) chelator derived from EGTA. Ca2+ binding causes a shift in the uv absorbance and fluorescence of the molecule. Parent compound of second generation fluorescent imaging agents such as Indo-1, Fura-2, q.q.v. Prepn: R. Y. Tsien, Biochemistry 19, 2396 (1980). Dissociation constants: R. Pethig et al., Cell Calcium 10, 491 (1989). Use as chelator: P. W. Marks, F. R. Maxfield, Anal. Biochem. 193, 61 (1991). Binding constants and fluorescence with heavy metals: A. Yuchi et al., Bull. Chem. Soc. Jpn. 66, 3377 (1993). Prepn of 19F-forms and use for intracellular Ca2+ measurement: G. A. Smith et al., Proc. Natl. Acad. Sci. USA 80, 7178 (1983); L. A. Levy et al., Am. J. Physiol. 252, C441 (1987). NMR determn of Ca2+ in brain by 5F-BAPTA: H. S. Bachelard et al., J. Neurochem. 51, 1311 (1988).

Chemical structure

Properties

uv max (free dye): 209, 254 nm (ε 3.8 × 104, 1.6 × 104). uv max (complexed form): 203, 274 nm (ε 4.1 × 104, 4.2 ×103).

Use

As calcium chelator; 19F labelled forms for measurement of intracellular calcium.