Table 2. Mass and melting temperature of the main proteins in this study, as well as number of cells N measured by FLIP and standard deviation σ (in µm²/s) of the average measured diffusion coefficients (shown in Figure 5) among the N cells.

Molecular Mass	GFP	ltPGK-GFP	ltPGK-FRET
	28 kDa	73 kDa	101 kDa
T m *	65±1°C	37±1°C	39±1°C
22°C	N = 4, σ = 6.5	N = 3, σ = 1.8	N = 2, σ = 2.0
27°C	N = 4, σ = 7.7	N = 4, σ = 4.1	N = 7, σ = 2.3
32°C	N = 3, σ = 6.1	N = 4, σ = 8.2	N = 4, σ = 5.2
37°C	N = 5, σ = 9.2	N = 3, σ = 2.0	N = 5, σ = 5.4

*In vitro; the in-cell melting temperature of the ltPGK-FRET mutant is ca. 2.5°C higher, and unknown for the ltPGK-GFP mutant.