INVITROGEN [MOLECULAR PROBES] CONSTANTS?

MAGNESIUM

See: http://probes.invitrogen.com/handbook/sections/1900.html

They have been adapted to the MAXC format assuming that, being derived from BAPTA, the hydrogen disassociation constants are the same (admittedly a "wild" assumption, but we have to start somewhere?).

In order of increasing Mg affinity:

	CALCIUM		MAGNESIUM
CHELATOR	Kd (nM)	MAXC	Kd (mM)	MAXC
BAPTA	136	6.970	22.5	1.77
Mag-Orange	12,000	3.02	3.9	2.53
Mag-Indo-1	?	?	2.7	2.69
Mag-Fura-Red	17,000	2.87	2.5	2.72
Mag-Fura-5	28,000	2.65	2.3	2.76
Mag-Fura-2	25,000	2.705	1.9	2.84
Mag-Green	6,000	3.325	1.0	3.12

 

 

 

 

 

The rest of the MAXC constants for BAPTA are: [set H4 to ZERO for most of the indicators above]

H1	H2	H3	H4
6.360	5.470	1.000	1.000
dH1	dH2	dH3	dH4
0.01	0.01	0.00	0.00

The Ca-BAPTA and Mg-BAPTA constants are:

CaM	CaHM		MgM	MgHM
6.970	?		1.770	?
dCaM	dCaHM		dMgM	dMgHM
4.70	?		?	?

If anyone has more precise values for any of the above, please let me know, cpatton@stanford.edu

These values are more likely to be valid the closer they are to the experimental conditions that Molecular Probes used to assess the Kd in the first place, 22C, pH 7.2, 0.110N