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BIOMEMBRANES. István Léránt. BIOMEMBRANES. Barriers Define the inside and the outside of the cells Sheetlike structures Closed bounderies Specific proteins serve as Pumps Channels Receptors Energy transducers. Comparision of various types of membranes. as a % of the total mass.
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BIOMEMBRANES István Léránt
BIOMEMBRANES Barriers Definetheinside and theoutside of thecells Sheetlikestructures Closedbounderies Specificproteinsserveas Pumps Channels Receptors Energytransducers A biomembránok felépítése
Comparision of varioustypesofmembranes as a % of thetotalmass A biomembránok felépítése
MEMBRANES • Membranesconsistmaily of • Lipids • Proteins • 1:1 ratio (1:4 -> 4:1) • Carbohydrates • Glycolipids • Glycoproteins • Lipidbilayer - barrier • Hydrophylic & hydrophobicsidechains • Specificproteinsas • Pumps • channels • Receptors Barriers Definetheinside and theoutside of thecells Sheetlikestructures Closedbounderies Specificproteinsserveas Pumps Channels Receptors Energytransducers A biomembránok felépítése
Comparision of variouslipidcompoments Neutrallipids Membranlipids Structure – form. Phospholipids Glycolipids Cholesterol Triacylglycerols Energystores • Fattycid(1) Fattycid(1) sphingosine sphingosine • Fattycid(2) Glycerol Fattyacid Fattyacud Glyerol Fattycid(2) Glu / Gal P P Choline Fattycid(3) Alcohol Ceramide Specificfunction Steroidalhormones Eicosanoids Vitamins (A, D, E, K) Phospholipids Glycoproteins BIOMEMBRANES A biomembránok felépítése
MEMBRANES Phosphatidicacid PHOSPHOLIPIDS PHOSPHOGLYCERIDES Sphingolipids - sphingomyelin Sn-1 – Fattyacid Sn-2 – Fattyacid – usuallyunsaturated, polyunsaturated ‘alcohol’ – choline ethanolamine serine inositol A biomembránok felépítése
MEMBRANES PHOSPHOLIPIDS PHOSPHOGLYCERIDES Sphingolipids - sphingomyelin A biomembránok felépítése
Digestion of phospholipidsby Specificphospholipaseenzymes phospholipase A1 phospholipase A2 Lysophospholipid X phospholipase C phospholipase D A biomembránok felépítése
víz Polarcomponent phosphate Glycerol „head” hydrophyl „Tail” hydrophob A biomembránok felépítése
MEMBRANES PHOSPHOLIPIDS PHOSPHOGLYCERIDES Sphingolipids - sphingomyelin A biomembránok felépítése
A sphingomyeline Fattyacids Phosphoricacid Sphingosine Ceramide Choline A biomembránok felépítése
Glycolipids A biomembránok felépítése
MEMBRANES • Lipidbilayer • Phospholipid, cholesterolration • Type of membrane • Dualinfluence of cholesterol A biomembránok felépítése
MEMBRANES A biomembránok felépítése
IN VITRO – PREPARATION OF LIPOSOMES A biomembránok felépítése
IN VITRO – PREPARATION OF LIPOSOMES A biomembránok felépítése
IN VITRO – PREPARATION OF LIPOSOMES A biomembránok felépítése
IN VITRO – PREPARATION OF LIPOSOMES • Outerlayer • phosphatidylcholine • Sphingomyelin • Innerlayer • phosphatidylethanolamine • phosphatidylserine • Lipidmovementinmembranes • Rotation • Lateraldiffusion • Flip-flop MEMBRÁNOK ASSZIMETRIÁJA A biomembránok felépítése
Rapid diffusion of memberanlipids and proteins • Flourescencerecoveryafterphotobleaching (FRAP) • Fluorescence Recovery After Photobleaching (FRAP) Membrancompoment is labelledbyfluorescentdye ~ 3 mm2surfacearea Bleaching A biomembránok felépítése
MEMBRAN PROTEINS Way of isolation: Periferialmembraneproteins pH changement Salt concentration Integralmembraneproteins Intensivetreatment Detergents Organicsolvents Hyrophobic, transmembranedomain (~ 25 hydrophobicaminoacids) Integral (a,b,c) and peripherial (d,e) membraneproteins A biomembránok felépítése
Structure of bacteriorhodopsine a-hélix Citoplazma felőli nézet A biomembránok felépítése
Covalentlyboundproteins Palmityl-group – HS-Cys THIOESTER C terminalCys -. Farnesyl-group GPI – ancor (glycosyl-phosphatydil-inositol) (enthanol-amin – P – mannose, GlcNac –Glycosylphosphatydilinositol GPI) A biomembránok felépítése
SINGER-NICHOLSON MODEL • Lipidbilayer • Integral – transzmembrane - proteins • Membrane • Lipidbilayer • Glycolipids (‘-’ charge) • Internalperipherialproteins • Fluid-mosaicmodel Twodimensionalsolution of membrane – lipids and globularproteins Solvent of integralproteins Lateraldiffusion of protein is free Permeabilitybarrier A biomembránok felépítése
LIPIDS OF BIOMEMBRANES Phospholipids Glycolipids Cholesterol Stearinicacidoctadecanoicacid, 18: 0 Oleicacid, cis-9-octadecenoic acidcis 18:1 Linolic, cis, cis-9,12-octadecadienoic acidcis,cis 18:2 A biomembránok felépítése
Membranefluidity and unsaturatedfattyacids + cholesterol A biomembránok felépítése
Membranfunctions Signaltransduction Signaltransformation Structure of membranes Barriers Definetheinside and theoutside of thecells Sheetlikestructures Closedbounderies Specificproteinsserveas Pumps Channels Receptors Energytransducers Signaltransduction Answer Second mesengers Hormons External signals Biochemical changement Receptor A biomembránok felépítése