Table 1 Summary of Trp fluorescence parameters measured for Ail-WT and its Trp mutants in various DPRs

From: Differential Contribution of Tryptophans to the Folding and Stability of the Attachment Invasion Locus Transmembrane β-Barrel from Yersinia pestis

 

Average lifetime (<τ>, ns)b

Anisotropy (r)b

Bimolecular quenching constant (kq, × 109 M−1 s−1)

DPRa

WT

W42F

W149F

WT

W42F

W149F

WT

W42F

W149F

700:1

3.62 ± 0.2

2.43 ± 0.2

3.17 ± 0.1

0.143

0.122

0.152

1.40

1.54

1.85

700:1 (D)

1.96 ± 0.0

1.68 ± 0.1

1.77 ± 0.1

0.068

0.070

0.062

-

-

-

1750:1

3.96 ± 0.1

2.93 ± 0.2

3.72 ± 0.3

0.140

0.123

0.159

1.33

1.36

1.77

1750:1(D)

2.10 ± 0.1

1.75 ± 0.1

1.87 ± 0.1

0.080

0.068

0.072

-

-

-

3500:1

3.97 ± 0.1

2.89 ± 0.1

4.34 ± 0.1

0.141

0.120

0.154

1.31

1.35

1.56

3500:1 (D)

2.18 ± 0.1

1.81 ± 0.0

1.86 ± 0.0

0.106

0.080

0.069

-

-

-

0:1 (U)

1.75 ± 0.1

1.66 ± 0.1

1.61 ± 0.1

0.050

0.046

0.047

4.18

4.31

4.78

0:1 (A)

0.32 ± 0.0c

0.14 ± 0.0c

0.20 ± 0.0c

0.123

0.143

0.142

-c

-c

-c

  1. aHere (D) represents the refolded protein denatured by the addition of 6.4 M GdnHCl and therefore retains the respective LDAO amounts. (U) is unfolded protein in 8.0 M GdnHCl and contains no LDAO. (A) is aggregated protein sample prepared in Tris-HCl pH 8.5 and contains 0.16 M GdnHCl.
  2. bAll samples were incubated for 48 h at 25°C before obtaining measurements. <τ> = Στ = αiτi
  3. cLifetimes could not be accurately determined due to interference from scattering. Hence, the kq values were also not calculated.
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