Biochemistry 2280A Lecture Notes - Lecture 20: Polyacrylamide Gel Electrophoresis, Sickle-Cell Disease, Hemolytic Anemia
11 May 2020
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Document Summary
Functions of peripheral membrane proteins: determine cell shape e. g. cytoskeleton, communication - intercell and intracell. Spectrin a protein found in red blood cells: two subunits interact with each other by winding around each other (helical layout), mutations in spectrin can cause haemolytic anaemia, by causing different sized red blood cells. Important because the spectrin causes a mesh like structure beneath the membrane, it interacts with other proteins in the rbc to connect them to the cytoskeleton tethered so have low mobility. Peripheral proteins of the rbc : spectrin mesh work (essential for shape change, actin mesh work, ankyrin. Transmembrane (integral) proteins : glycophorin, band 3. Phospholipids move about 2 x 10-4cm per second, compared to proteins which move much slower at between 10-4-10-6cm per second. The mobility of band 3 and glycophorin are restricted by the cytoskeleton (mesh) of the rbc"s so the membrane proteins are not freely diffusible.
