340 likes | 500 Views
- 2013/2014 - 3D Structures of Biological Macromolecules Exercise: Membrane Proteins. Jürgen Sühnel jsuehnel@fli-leibniz.de. Leibniz Institute for Age Research, Fritz Lipmann Institute, Jena Centre for Bioinformatics Jena / Germany.
E N D
- 2013/2014 - 3D Structuresof Biological Macromolecules Exercise: Membrane Proteins Jürgen Sühnel jsuehnel@fli-leibniz.de Leibniz Institute for Age Research, Fritz Lipmann Institute, Jena CentreforBioinformatics Jena / Germany Supplementary Material: http://www.fli-leibniz.de/www_bioc/3D/
Cholesterol, a ConstituentoftheCell Membrane Without cholesterol, cell membranes would be too fluid, not firm enough, and too permeable to some molecules. In other words, it keeps the membrane from turning to mush. Cholesterol is an amphipathic molecule, meaning, like phospholipids, it contains a hydrophilic and a hydrophobic portion. Cholesterol's hydroxyl (OH) group aligns with the phosphate heads of the phospholipids. The remaining portion of it tucks into the fatty acid portion of the membrane.
Membrane Proteins • Integral membrane proteins (penetrating the lipid bilayer; permanently attached) [Insulin receptor, rhodopsin, …] • Integral polytopic membrane proteins (transmembrane proteins) • Integral monotopic membrane proteins • Peripheral membrane proteins (external bound with non-covalent bonds; temporarily attached) [Enzymes: phospholipase …] • Lipid-anchored proteins (external bound with covalent bonds) [G proteins …]
Integral Polytopic Membrane (Transmembrane) Proteins • Schematicrepresentationoftransmembraneproteins: • a singletransmembraneα-helix (bitopicmembraneprotein) • a polytopictransmembraneα-helicalprotein • a polytopictransmembraneβ-sheetprotein
Integral Monotopic Membrane Proteins • Schematicrepresentationofthe different typesofinteractionbetweenmonotopicmembraneproteinsandthecellmembrane: • interactionby an amphipathicα-helix parallel tothemembrane plane (in-plane membranehelix) • interactionby a hydrophobicloop • interactionby a covalentlyboundmembranelipid (lipidation) • electrostaticorionicinteractionswithmembranelipids (e.g.through a calciumion)
Membrane Protein Databases http://blanco.biomol.uci.edu/mpstruc/listAll/list
Membrane Protein Databases http://blanco.biomol.uci.edu/mpstruc/listAll/list
Membrane Protein Databases www.mpdb.tcd.ie
Membrane Protein Databases opm.phar.umich.edu
Membrane Protein StructureClasses January 2013 January 2014
Transmembrane Protein (Halorhodopsin) alpha-helical polytopic
Transmembrane Protein (Halorhodopsin) alpha-helical 1e12
Transmembrane Protein (Halorhodopsin) alpha-helical 1e12
Transmembrane Protein (Outer Membrane Protein A) beta-barrel
Transmembrane Protein (Outer Membrane Protein A) beta-barrel 1qjp
Transmembrane Helix Prediction Server www.cbs.dtu.dk/services/TMHMM/
FASTA Format >sp|P16102|BACH_HALSA Halorhodopsin OS=Halobacterium salinarium (strain ATCC 700922) MSITSVPGVVDAGVLGAQSAAAVRENALLSSSLWVNVALAGIAILVFVYMGRTIRPGRPR LIWGATLMIPLVSISSYLGLLSGLTVGMIEMPAGHALAGEMVRSQWGRYLTWALSTPMIL LALGLLADVDLGSLFTVIAADIGMCVTGLAAAMTTSALLFRWAFYAISCAFFVVVLSALV TDWAASASSAGTAEIFDTLRVLTVVLWLGYPIVWAVGVEGLALVQSVGVTSWAYSVLDVF AKYVFAFILLRWVANNERTVAVAGQTLGTMSSDD
Transmembrane Helix Prediction Server (1e12) www.cbs.dtu.dk/services/TMHMM/
Transmembrane Helix Prediction Server (1e12) www.cbs.dtu.dk/services/TMHMM/
Split Server split.pmfst.hr/split/4/
Split Server Prediction (1e12) split.pmfst.hr/split/4/
Split Server Prediction (1qjp) split.pmfst.hr/split/4/
Other Tools for Membrane Protein StructurePrediction http://www.stats.ox.ac.uk/~kelm/medeller/
Transmembrane Prediction Sites http://expasy.org/tools/
Transmembrane Prediction Sites http://www.sacs.ucsf.edu/Links/transmem.html