The spelling of the word "membranin" is based on the root word "membrane," which refers to a thin, flexible material that surrounds and separates various parts of an organism or system. The "-in" suffix is commonly used to indicate a protein or other substance that is associated with or derived from the original term. In IPA phonetic transcription, the word would be pronounced /mɛmˈbreɪnɪn/, with stress on the second syllable.
A protein derived from the capsule of the crystalline lens of the eye.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.