The origin of characteristic torocyte-like shape of vesicles derived from transverse tubule in triad junction of skeletal muscles is studied theoretically. Two possible mechanisms are suggested. The first is the minimization of membrane bending energy where the special intermediate molecular structures in the central region of the vesicle is assumed to protect the opposing bilayers to come in the direct contact. The second mechanism is based on the assumption that the characteristic shape of the vesicles may be explained by non-homogenous lateral distribution of anisotropic membrane components.
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