Biophysical studies of membrane proteins/peptides. Interaction with ...

More documents

Recommendations

Info

sphingomyelin, the most abundant sphingolipid, which is a significant component of animal plasma membranes. 1.2.1.3. Glycolipids Both glycerolipids and sphingolipids can be linked to a carbohydrate in their headgroups, giving rise to a glycolipid. Glycolipids play important roles in the interactions of the cell with its surroundings. Glycoglycerolipids are very abundant in chloroplast membranes, as well as in blue algae and bacteria. They are however rarely found in animals (Gennis, 1989). In glycosphingolipids, one or more carbohydrates are linked to the terminal hydroxyl group of the sphingosine backbone. The simplest form of glycosphingolipid is a cerebroside that contains a single carbohydrate residue, either glucose or galactose. Complex glycosphingolipids called gangliosides present one or two branched carbohydrate chains containing sialic acid groups. Glycosphingolipids are as a rule located in the outer surface of the plasma membrane with varying concentrations (2-10 %), and are particularly abundant in the nervous system. 1.2.1.4. Sterols The basic structure of sterols is a four ring hydrocarbon. This structure confers the molecule much more rigidity than other lipids. The most important sterol in animal membranes is cholesterol (Fig. I.3). In cholesterol, a hydrocarbon chain is linked to one end of the ring system and a hydroxyl group is attached to the other end of the structure, this being the polar headgroup of the molecule. In the lipid bilayer the molecule is oriented parallel to the fatty-acid chains of other lipids while the hydroxyl group interacts with nearby headgroups. Cholesterol is only found in eukaryotes, particularly in animal plasma membranes, lysosomes, endosomes and Golgi apparatus. The concentration of cholesterol is especially high in the animal plasma membrane (20 - 30 %). In plants cholesterol exists in low amounts, and other sterols are present, namely sitoesterol and stigmasterol. Ergosterol is found in yeast and other eukaryotic microorganisms. 6
INTRODUCTION: BIOMEMBRANES Figure 1.3 – Structure of cholesterol (From Berg et al., 2002). 1.3. Lipid asymmetry across the bilayer Lipid composition in the cytoplasmatic and exoplasmatic leaflets of the bilayer is asymmetric. In plasma membranes, the cytoplasmatic leaflet is enriched in PE, PS, and PI, while in the exoplasmatic leaflet lipids like PC, glycolipids, sphingomyelin and cholesterol exist in higher concentrations. One of the factors contributing to this lipid asymmetry is the site of synthesis of the lipids in the membranes of the endoplasmic reticulum and Golgi, as it dictates the plasma membrane leaflet where the lipid is to be inserted. In this way, addition of carbohydrates to glycolipids is done through the luminal side of the Golgi apparatus that is topologically equivalent to the exterior of the cell. This however does not account for all asymmetry observed and the action of ATP-powered transport proteins called translocases is essential (Lodish et al., 2000). However, asymmetry would be lost if lipids easily crossed from one leaflet to the other. In fact, in protein free liposomes, the kinetics of this process is extremely slow, on the order of hours/days. This is due to the extremely energetically unfavourable process of inserting the polar headgroup of a lipid in the hydrophobic membrane interior. Lipid asymmetry is of functional importance, and many cytosolic proteins bind to specific lipid headgroups (like PS or PI) in the cytosolic leaflet of the bilayer. Animals also use phospholipid asymmetry in the plasma membrane of cells as a control to distinguish between dead and healthy cells, as when animal cells undergo programmed cell death, or apoptosis. In this case, PS lipids that are normally found enriched in the cytosolic leaflet, distribute between both leaflets of the bilayer. This functions as a 7
Page 1: UNIVERSIDADE TÉCNICA DE LISBOA INS
Page 4 and 5: Fernandes, F., Loura, L. M. S., Fed
Page 6 and 7: Ao Pedro e Hugo, amigos de longa da
Page 8 and 9: 2.2. - Peptides as models 2.3. - Am
Page 11 and 12: ABBREVIATIONS AND SYMBOL LIST ABBRE
Page 13: RESUMO RESUMO As biomembranas são
Page 17 and 18: SINOPSE SINOPSE Nas últimas duas d
Page 19 and 20: SINOPSE podem fornecer informação
Page 21 and 22: SINOPSE aceitantes. Dadores mais pr
Page 23 and 24: OUTLINE OUTLINE The last two decade
Page 25 and 26: OUTLINE membranes with a distributi
Page 27: OUTLINE BAR domains (tubulation of
Page 30 and 31: ion diffusion, as the energy requir
Page 32 and 33: acid. If no more groups are linked
Page 36 and 37: signal for neighbouring cells to ph
Page 38 and 39: functional role in process such as
Page 40 and 41: in the L α phase, while lateral di
Page 42 and 43: 1.7. Lateral heterogeneity in lipid
Page 44 and 45: the vesicle through bilayer deforma
Page 46 and 47: Figure I.9 - Depiction of the sever
Page 48 and 49: Figure I.11 - Experimentally obtain
Page 50 and 51: drying into a film and ressuspensio
Page 52 and 53: deactivating agents. Zwitterionic d
Page 54 and 55: amphipatic helices (see Section 2.3
Page 56 and 57: size corresponding to the hydrophob
Page 58 and 59: changes abruptly in the interfacial
Page 60 and 61: thickness of the bilayer (Section 1
Page 62 and 63: some α-helical membrane proteins a
Page 64 and 65: The formation of a lipid population
Page 66 and 67: homogeneous distribution of lipids
Page 68 and 69: Figure I.20 - Relative binding cons
Page 70 and 71: 2.9. Lipid phase preferential parti
Page 72 and 73: In Figure I.21, theoretical simulat
Page 75 and 76: PROTEIN-PROTEIN AND PROTEIN-LIPID I
Page 77 and 78: PROTEIN-PROTEIN AND PROTEIN-LIPID I
Page 79: PROTEIN-PROTEIN AND PROTEIN-LIPID I
Page 83 and 84: 2430 Biophysical Journal Volume 85
Page 85 and 86:
2432 Fernandes et al. Coat protein
Page 87 and 88:
2434 Fernandes et al. leads to an a
Page 89 and 90:
2436 Fernandes et al. FIGURE 4 (A)
Page 91 and 92:
2438 Fernandes et al. section of th
Page 93 and 94:
2440 Fernandes et al. tein oligomer
Page 95:
QUANTIFICATION OF PROTEIN-LIPID SEL
Page 98 and 99:
FRET Study of Protein-Lipid Selecti
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 107 and 108:
BINDING OF INHIBITORS TO A PUTATIVE
Page 109 and 110:
BINDING OF INHIBITORS TO A PUTATIVE
Page 111:
INTERACTION OF THE INDOLE CLASS OF
Page 114 and 115:
5272 Biochemistry, Vol. 45, No. 16,
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 123:
BINDING ASSAYS OF INHIBITORS TOWARD
Page 126 and 127:
1778 F. Fernandes et al. / Biochimi
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
apparently the most significant as
Page 138 and 139:
110
Page 140 and 141:
Introduction Quinolones are broad-s
Page 142 and 143:
[9-12]. Having this into considerat
Page 144 and 145:
any case, very similar, probably wi
Page 146 and 147:
placement of the protein around the
Page 148 and 149:
⎛ II t ⎛ R ⎞ 0 ρ () t = exp
Page 150 and 151:
APPENDIX - Derivation of the FRET r
Page 152 and 153:
2 2w J ( t) = '2 R − R + w / 1
Page 154 and 155:
[14] L. Plançon, M. Chami, L. Lete
Page 156 and 157:
acceptors) (Eqs. 4-6) (⋅-⋅-⋅)
Page 158 and 159:
FIGURE 1A FIGURE 1B 130
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
136
Page 166 and 167:
dynamin. Soon after, the same group
Page 168 and 169:
140
Page 170 and 171:
142
Page 172 and 173:
Introduction Control of membrane re
Page 174 and 175:
Steady-state fluorescence measureme
Page 176 and 177:
Rho-DOPE (acceptor). The increase o
Page 178 and 179:
where η is the viscosity of the me
Page 180 and 181:
ound conformation of the BAR domain
Page 182 and 183:
19. Fernandes, F., L. M. S. Loura,
Page 184 and 185:
Figure Legends Fig.1: N-terminal am
Page 186 and 187:
FIG. 1A FIG.1B 17
Page 188 and 189:
FIG. 3A FIG. 3B 19
Page 190 and 191:
FIG.5A 21
Page 192 and 193:
FIG 6. 23
Page 194 and 195:
FIG. 8 A B 25
Page 196 and 197:
The signalling functions of PI(4,5)
Page 198 and 199:
172
Page 200 and 201:
174
Page 202 and 203:
zoxadiazol (NBD)-PC were obtained f
Page 204 and 205:
Fig. 3. Fluorescence decays of diph
Page 206 and 207:
CONCLUSIONS VII CONCLUSIONS Chapter
Page 208 and 209:
CONCLUSIONS constants recovered by
Page 210 and 211:
CONCLUSIONS Chapter IV ‐ Binding
Page 212 and 213:
CONCLUSIONS Chapter VI - Clustering
Page 214 and 215:
FINAL CONSIDERATIONS AND PROSPECTS
Page 216 and 217:
BIBLIOGRAPHY IX BIBLIOGRAPHY Albert
Page 218 and 219:
BIBLIOGRAPHY Phosphatidylinositol 4
Page 220 and 221:
BIBLIOGRAPHY Glaubitz, C., Grobner,
Page 222 and 223:
BIBLIOGRAPHY Koehorst, R. B. M., Sp
Page 224 and 225:
BIBLIOGRAPHY Mishra, V. K., Palguna
Page 226 and 227:
BIBLIOGRAPHY Pluschke, G., Hirota,
Page 228 and 229:
BIBLIOGRAPHY Sperotto, M. M., and M
Page 230:
BIBLIOGRAPHY Williamson, I. M., Alv
show all

Biophysical studies of membrane proteins/peptides. Interaction with ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?