Inhaltszusammenfassung

The major light-harvesting chlorophyll a/b protein (LHCIIb) of higher plants is one of the few membrane proteins that can be refolded in vitro. During folding, the apoprotein is assembled with pigments to form a structurally authentic and functional pigment-protein complex. All reconstitution procedures used so far include solubilization of the apoprotein in sodium dodecyl sulfate (SDS) where the protein adopts approximately half of its a-helical folding present in the native structure. This ...The major light-harvesting chlorophyll a/b protein (LHCIIb) of higher plants is one of the few membrane proteins that can be refolded in vitro. During folding, the apoprotein is assembled with pigments to form a structurally authentic and functional pigment-protein complex. All reconstitution procedures used so far include solubilization of the apoprotein in sodium dodecyl sulfate (SDS) where the protein adopts approximately half of its a-helical folding present in the native structure. This paper shows that this preformed a-helix is not a prerequisite for LHCIIb folding in vitro. The apoprotein can also be reconstituted starting from a solution in guanidinium hydrochloride (Gnd) where the protein contains no detectable helical structure. Reconstitution yields are somewhat lower in the Grid than in the SDS procedure, but the reconstitution products exhibit very similar biochemical and spectroscopic properties. The kinetics of LHCIIb assembly, as assessed by time-resolved fluorescence measurements, are virtually the same in both reconstitution procedures. This demonstrates that the initiation of a-helix formation is not a rate-limiting step in LHCIIb apoprotein folding.» weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
2.12 - Pflanzenwissenschaften

DDC Sachgruppe:
Pflanzen (Botanik)