Polarizable Water Martini3 - Pore Formation Lipid Bilayers

[ignasisg]

Hi all,

I’d like to open a discussion around some questions I’m currently facing:

1.-I’m interested in studying pore formation in lipid bilayers by applying pressure. From what I understand, polarizable water (PW) is especially important when water molecules need to interact closely with hydrophobic regions. Would using a polarizable water model be advisable in this case to accurately capture pore formation dynamics?

2.-If so, is there any information on when a polarizable water model will be available for Martini 3? As far as I know, it currently only exists for Martini 2.

3.-I’m using polyply to generate my lipid bilayer, which I believe defaults to Martini 3 topologies. However, I’d like to use polarizable water—which is only available for Martini 2. Is it possible or advisable to mix Martini 2 PW with Martini 3 lipids? Intuitively, this seems problematic due to force field inconsistencies, but I haven’t found a clear workaround. Should I consider running everything under Martini 2 instead, even if that means using an older force field?

Any guidance or shared experiences would be greatly appreciated.

Best regards,

[WangLiguo-kyrie]

Polarizable Water could imporve the dielectric properties of water, but I don't know why you believe "polarizable water (PW) is especially important when water molecules need to interact closely with hydrophobic regions"? I don't think the interaction between lipid tail (C bead) and two water model would be significantly different.
Currently we don't have PW for Martini3 yet and combination usage is not allowed. But if necessary, running everything under Martini2 is still one option.

[ignasisg]

I wasn't entirely sure. I've observed that it tends to yield results closer to the AA control in electroporation experiments, but I suspect this may be due to the fact that electroporation relies on charge transport mechanisms. Thanks for your input!