title: Analyzing the effects of hydrophobic mismatch on transmembrane α-helices using tryptophan fluorescence spectroscopy.
abstract: Hydrophobic matching between transmembrane protein segments and the lipid bilayer in which they are embedded is a significant factor in the behavior and orientation of such transmembrane segments. The condition of hydrophobic mismatch occurs when the hydrophobic thickness of a lipid bilayer is significantly different than the length of the membrane spanning segment of a protein, resulting in a mismatch. This mismatch can result in altered function of proteins as well as nonnative structural arrangements including effects on transmembrane α-helix tilt angles, oligomerization state, and/or the formation of non-transmembrane topographies. Here, a fluorescence-based protocol is described for testing model transmembrane α-helices and their sensitivity to hydrophobic mismatch by measuring the propensity of these helices to form non-transmembrane structures. Overall, good hydrophobic matching between the bilayer and transmembrane segments is an important factor that must be considered when designing membrane proteins or peptides.
authors: Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ, USA.
authors: Gregory A
authors: GA
authors: Caputo
mesh_terms: D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D008565:Membrane Proteins; D010455:Peptides; D014364:Tryptophan