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. Author manuscript; available in PMC: 2017 Mar 29.
Published in final edited form as: Biochemistry. 2016 Mar 7;55(12):1873–1886. doi: 10.1021/acs.biochem.6b00067

Table 3.

Terbium(III) Luminescence Decay Parameters Recovered upon Binding to DREAM and DREAM Constructsa

τ1 (ms) f1 τ2 (ms) f2
CaM 1.38 1.00
CaM with TFPb 0.46 0.31 1.36 0.69
DREAM(Δ64) 0.86 0.59 2.22 0.14
DREAM(Δ64) with Mg2+ 0.74 0.54 2.05 0.24
DREAM(Δ64)(a)c 0.58 0.27 2.00 0.69
DREAM(Δ64)(b)c 0.46 0.17 2.04 0.77
DREAM(Δ64)(c)c with NS5806 0.43 0.58 1.83 0.39
DREAM(Δ160) 0.75 0.47 2.16 0.29
DREAM(Δ160) with Mg2+ 0.63 0.41 2.03 0.37
DREAM(E186Q) 0.62 0.50 2.02 0.27
DREAM(E186Q) with Mg2+ 0.48 0.47 1.58 0.42
DREAM(E234Q) 0.63 0.27 1.75 0.46
DREAM(E234Q) with Mg2+ 0.45 0.31 1.70 0.48
a

All shown parameters were recovered using a triple or double discrete exponential decay; the error of the reported values is 2.5% on average. All experiments were conducted at room temperature (~20 °C) at protein concentration of 20 μM with addition of 80 μM Tb3+ for CaM and 40 μM Tb3+ for DREAM constructs. An additional lifetime of ~80 μs was resolved for all DREAM constructs, likely due to parasitic light or PMT recovery delay, and is not shown.

b

Measured in the presence of 131 μM TFP.

c

The protein concentration for these experiments was 10 μM in the presence of (a) 100 mM NaCl, (b) 100 mM NaCl and 10 mM LDAO, or (c) 100 mM NaCl, 10 mM LDAO, and 31 μM NS5806.