Table 1 Biophysical characterization of mTFP1 cp variants.

wt, wild type.

mTFP1Extinction
coefficient ε
(M−1 cm−1)(× 10−3)*
Quantum yield
Φ
BrightnessPhotostability t0.5
(s)
Maturation t0.5
(min)§
wt670.85576313
cp105640.81525034
cp159650.81535315
cp175580.73426321
cp227690.72506014

*Measured at 462 nm.

†Product of Φ and ε × 10–3. Φ of the wt protein was reported previously (13). Φ of cps was calculated according to Topell and Glockshuber (15).

‡Time to bleach by 50%. Bleaching was measured by live-cell imaging in HEK293T cells exposed to a 440-nm LED light power of 100%. For details, see note S1 and Materials and Methods.

§Maturation was measured at 25°C and pH 7.9.