chapter  7
24 Pages

7Chapter Identi cation of Carotenoids in Photosynthetic Proteins: Xanthophylls of the Light Harvesting Antenna

Principles and Challenges ..................................................................................................... 114 7.3 Localization and Functions of Xanthophylls in Light Harvesting Antenna of Plants ......... 117

7.3.1 The Need for Photosynthetic Antenna ..................................................................... 117 7.3.2 Structure of the Photosystem II Antenna: Xanthophylls in LHCII Structure .......... 117 7.3.3 Functions of Xanthophylls in the Antenna: A Structural Perspective ..................... 118 7.3.4 The Need for Identi cation of Xanthophylls In Vivo ............................................... 119

7.4 Principles of Identi cation of Xanthophylls In Vivo ............................................................ 119 7.5 Identi cation of Xanthophylls Associated with the Transmembrane Helixes of

LHCII Antenna Complex: Neoxanthin and Lutein .............................................................. 121 7.5.1 Identi cation of Neoxanthin: The 9-cis Requirement for a Xanthophyll in the

C-Helix Domain ....................................................................................................... 122 7.5.2 Discovery of the Two Optically Different Luteins in LHCII ................................... 123 7.5.3 Identi cation of the Chlorophyll Excitation Quencher in Aggregated LHCII .........124