title: On the dissociation constants of BAPTA-type calcium buffers.
abstract: We have determined or redetermined the calcium dissociation constants of seven BAPTA-type buffers with KD's in the range from 0.4 microM to about 20 mM in 300 mM KCl. These include four newly synthesized ones: 5-nitro BAPTA; 5,5'-dinitro BAPTA; 5-methyl-5'-nitro BAPTA; and 5-methyl-5'-formyl BAPTA. Moreover, we tabulate dissociation constants or KD's for BAPTA and eleven BAPTA-type buffers, compare most of them with an empirical curve based upon so-called Hammett values, and predict KD's for several still unsynthesized but potentially valuable buffers.
authors.affiliation: Marine Biological Laboratory, Woods Hole, Massachusetts.
authors.forename: R
authors.initials: R
authors.lastname: Pethig
authors.forename: M
authors.initials: M
authors.lastname: Kuhn
authors.forename: R
authors.initials: R
authors.lastname: Payne
authors.forename: E
authors.initials: E
authors.lastname: Adler
authors.forename: T H
authors.initials: TH
authors.lastname: Chen
authors.forename: L F
authors.initials: LF
authors.lastname: Jaffe
mesh_terms: D002021:Buffers; D002118:Calcium / Q000378:metabolism*; D004492:Edetic Acid / Q000138:chemical synthesis* / Q000494:pharmacology; D004952:Esters; D006868:Hydrolysis; D007700:Kinetics; D008024:Ligands; D008970:Molecular Weight
chemical_list: D002021:Buffers; D004952:Esters; D008024:Ligands; D004492:Edetic Acid; D002118:Calcium