1. Jamming and no nanosilos in pure DPPC:POPG 7:3
25mN/m
30mN/m
-At higher pressures, there is a loss of disordered fluid phase (lower height)
-FM bright phase associated with “fluid” region is as tightly packed as the condensed phase at higher pressure
-At 70mN/m, monolayer is solid (‘jammed’)
60mN/m
70mN/m

2. Nanosilos and de-jamming of DPPC:POPG 7:3 w/ peptide
SPB125
SPB925
AFM depositions done at 25C on a
3.18mPa·sec subphase at ∏=60mN/m
Nanosilo size distributions:
SPB125
SPB925
radius
height
3, 9, 14nm
4nm
50-150nm
100nm
even at high pressures (60mN/m)
LC domains remain separated by
disordered granular phase with all
four peptides
disordered granular phase allows
for changes in S(q) and the new
de-jamming stress
relaxation pathway A
LC domains: equal height (brighter, uniform) [dark phase on FM]
disordered phase: granular with LC islands and lower (1nm) fluid phase
coexisting with nanosilo stacks [bright phase on FM]

3. Nanosilos and de-jamming of DPPC:POPG 7:3 w/ peptide
SPB125Nflex
SPB1125
Nanosilo size distributions:
125Nflex
SPB1125
radius
height
2-3nm
3nm
35-40nm
50nm
nanosilos also smeared on imaging
indicating they were less stable
tryptophan 9 plays a role
in nanosilo stability
the N-terminus clearly has
some structural specificity
due to the poly-P sequence
that greatly enhances peptide
mediated nanosilo formation
nanosilo size: SPB125 >> SPB925, 125Nflex, 1125

4. Glycerol
using glycerol/water solutions the subphase viscosity is modulated between 0.89 and 114 mPa•sec
the most striking distinction in monolayer behavior between the different subphases subphases is
mode of collapse at near zero surface tensions.
system: DPPC:POPG 7:3 monolayer at 25oC under Argon compressed at 0.1mm/sec
0% glycerol (0.89 mPa•sec)
10% glycerol (1.15 mPa•sec)
get movie called DV_0%.mov
get movie called DV_10%.mov

5. system: DPPC:GM1 ? monolayer at 30oC compressed at 0.1mm/sec