Biology 2382B Lecture Notes - Glycosylphosphatidylinositol, Partition Coefficient, Uniporter
21 May 2013
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Document Summary
Membrane proteins carry out the biological functions of membranes they are all asymmetric. Three types of membrane proteins: integral: transmembrane domain (1-extracellular and 1-exoplasmic, peripheral: bound to a membrane protein (links integral to cytoskeleton, lipid linked: bound directly to lipids in plasma membrane. Integral membrane proteins asymmetric contain 3 distinct domains. Transmembrane hydrophobic: secondary/tertiary structure that span the lipid, helices (20-25 hydrophobic aa) bilayers. Arg and lys (charged aa) near cytosolic side. Anchoring transmembrane protein (don"t want to enter membrane and interact with hydrophobic tails) Interact with polar head groups: barrels hydrophobic shape that can be a transmembrane domain. Lipid-linked proteins anchored to membrane by lipophilic adduct (through bonds) Acylation (cytosolic) attaching protein to plasma membrane through n terminal glycine residue. Prenylation (cytosolic) attaching protein to plasma through cys residue at or near c terminal domain. Glycosylphophatidylinositol (gpi always exterior) add sugars and phosphoethanolamine, Gpi anchor (protein will not interact with cytoskeleton)
