Pore Size Distributions Related with Spontaneous Purple Membrane Stacking in Porous Hydrogels

Pore size distributions in hydrogels immobilizing purple membrane (PM) are elucidated by focusing on a relationship with PM stacking. PM stacking, which is useful for engineering applications, occurred spontaneously in porous hydrogels. Recently, it is suggested that porous gel network generations are essential for PM stacking. Here, to clarify a relationship with pore size, optical microscopic observations for hydrogels immobilizing PM were carried out. The results showed that PM stacking occurred at porous gels with a larger pore size than PM long axis length, while it did not occur in the smaller pores. These strongly suggest the appropriate pore size for PM stacking.