Table 1.

Quenching by MB of the intrinsic fluorescence of purified pig brain PMCA (brainPMCA) and of purified yeast hPMCA4b, reconstituted in PS or PC. Fluorescence measurements were performed as indicated in the Materials and Methods and data were analyzed by linear regression fit to the Stern–Volmer equation (R² > 0.93 in all cases).

Sample	[Tau] (nM)	KSV (µM−1)	Kd (µM)
BrainPMCA-PS	0	0.019 ± 0.001	52.6 ± 2.5
	0.1	0.019 ± 0.001	52.6 ± 2.5
	7.5	0.027 ± 0.001	37.0 ± 1.9
BrainPMCA-PC	0	0.0165 ± 0.001	60.6 ± 3.2
	7.5	0.021 ± 0.001	47.6 ± 2.3
	100	0.032 ± 0.001	31.3 ± 1.5
hPMCA4b-PS	0	0.014 ± 0.001	71.4 ± 3.7
	0.1	0.0275 ± 0.001	36.4 ± 2.6
	7.5	0.035 ± 0.001	28.6 ± 1.3
hPMCA4b-PC	0	0.019 ± 0.001	52.6 ± 2.8
	7.5	0.019 ± 0.001	52.6 ± 2.7
	100	0.030 ± 0.001	33.3 ± 1.9