CH250 Lecture Notes - Lecture 56: Membrane Transport Protein, Membrane Transport, Isoleucine
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Figure 6. 36 the human mitochondrial voltage-dependent anion channel (vdac) protein is a passive membrane transporter in the porin protein family. a. This transport protein contains a transmembrane -barrel structure with 19 strands surrounding a large interior channel 3 nm in diameter. b. Top view of a space-filling model of the same porin protein, with hydrophobic nonpolar residues oriented mostly outward (valine, leucine, isoleucine) and hydrophilic and charged groups oriented mostly inward (serine, threonine, arginine, lysine, aspartate). Figure 6. 42 human aquaporin 5 is expressed in salivary and sweat glands and in the cornea of the eye. a. The water channel of one monomer of aquaporin 5 is at the center of six transmembrane helices. The channel is densely packed with h2o molecules that pass through the channel in response to an osmotic gradient. b. homotetrameric aquaporin 5 contains a water channel in each subunit.
