Table 1.
A-40b | A8V2-40b | A5V5-40 | A2V8-40 | V-40 | |
---|---|---|---|---|---|
Compositiona | 100% A | 80% A / 20% V | 50% A / 50% V | 20% A / 80% V | 100% V |
Tc,EPR/°Cc | - | 70 ± 1 | 52 ± 1 | 44 ± 1 | 38 ± 1 |
Tc,Turbidimetry/°C | 69.2 | 60.4 | 49.7 | 40.8 | 34.4 |
A-80 | A8V2-80 | A5V5-80 | A2V8-80 | V-80 | |
Composition | 100% A | 80% A / 20% V | 50% A / 50% V | 20% A / 80% V | 100% V |
Tc,EPR/°C | 70 ± 1 | 54 ± 1 | 36 ± 1 | 34 ± 1 | 32 ± 1 |
Tc,Turbidimetry/°C | 66.4 | 52.8 | 41.1 | 32.9 | 28.1 |
“Composition” denotes the composition of the guest residues Xaa, in the otherwise always identical Val-Pro-Gly-Xaa-Gly sequence.
The discrepancy between Tc,EPR and Tc for ELP A/ A8V2-40 is a consequence of large amounts of residual water in the ELP aggregates above the LCST, which screen the hydrophobic interaction between 16-DSA and the ELP aggregates. Such interactions between 16-DSA and A-y ELPs can only be observed at temperatures significantly above the LCST, since increased dehydration of the ELPs is needed for significant interaction between 16-DSA and the aggregates.
Note that Tc,EPR denotes the onset of observable interaction between the ELP and 16-DSA, while Tc denotes the cloud point of the solution (i.e., the temperature of the inflection point in a turbidity profile).