Table 1.
Comparison of the surface properties of B6.4-13, B13-17 and B6.4-17 (44) at TO/W and A/W interface.
| At TO/W interface | At A/W interface | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Peptides | γeq (mN/m) at c (M) |
ΠMAX (mN/m) |
ε (mN/m) ΔV<25% |
ϕ (degree) |
ε′ (mN/m) | Exch. off |
Pushed off |
Limiting A (Å2/aa) |
Collapse Π (mN/m) |
A at collapse (Å2/aa) |
| B6.4-13 | 14.1 (1.5×10−7) |
16.7 | 25.6±6.5 | 16.5±7.7 | 25.6±7.1 | No | Partly | 16.6 | 31 | 12.2 |
| B13-17 | 12.6 (1.5×10−7) |
19.2 | 38.0±7.3 | 4.5±3.8 | 37.8±7.4 | No | Partly | 17.8 | 35 | 13.3 |
| B6.4-17 (44) | 13 (1.9×10−7) |
16.7 | 32.3±3.9 | 10.3±4.6 | 31.8±4.2 | No | Partly | 8.6 | 28±1 | 7.3 |
γeq, the equilibrium interfacial tension; ΠMAX, the maximum pressure that peptide could withstand without being ejected from the interface; ε, visco-elastic modulus; ϕ, viscous phase angle, a phase difference between dγ and dA; ε′, elastic component, the real part of modulus; Exch. off, exchanged off, whether the peptide partly desorbs from the interface during buffer exchange procedure; Pushed off, whether the peptide desorbs from the interface when compressed the interface; Limiting A, extrapolation of the steep part of the Π-A isotherm to the baseline gives a limiting area; Collapse Π, the surface pressure at which there is a abrupt change in the slope of the Π-A isotherm above which the isotherm is not readily reversible; A at collapse, the surface area per amino acid when the peptide monolayer collapse.