The lipid composition of the eye lens membrane differs between the species. In the lower life span animals, eye lenses have phosphatidylcholine as a major component, while lenses have sphingomyelins as a major phospholipid in higher life span animals. Here, we study the mechanical properties of model membrane made of mouse phospholipid composition with Chol/PL mixing ratio of 0 and 1, respectively using Atomic force microscopy (AFM). The model membrane's height image with 0 mol% Chol shows two phases: solid ordered (so) and liquid disordered (ld). The height difference between the two phases is ~ 1 nm. The model membrane with Chol/PL mixing ratio of 1 exhibit only a single-phase known as liquid-ordered phase (lo). Thus, the membrane roughness of Chol/PL mixing ratio of 1 is 152±8 pm which is significantly lower than the roughness of membrane with Chol/PL mixing ratio of 1, which is 241±36pm. Similarly, the average breakthrough force for the Chol/PL mixing ratio of 0 is 5.4±0.41 nN, while for Chol/PL mixing ratio of 1, the average breakthrough force is 4.88±0.58 nN. We speculate that this slight difference in the membrane breakthrough force may be due to two phases in the 0 mol% Chol-containing membrane.
Marosvari, Mason; Mortimer, Max-Florian; Khadka, Nawal K.; Timsina, Raju; and Mainali, Laxman, "AFM Study of Model Membrane Made of Mouse Lens Phospholipids" (2021). 2021 Undergraduate Research Showcase. 7.