Eggink, L.L.， Park, H. and Hoober, J.K. 2001的附录。叶绿素b在光合作用中的作用:假设。植物生物学杂志1:2。
本文提出叶绿素(Chl) a和b在叶绿体类囊体膜的捕光复合物(lhc)中结合的特异性是由于Mg在Chl b中具有较强的Lewis酸性质。Chl b与载脂蛋白之间形成的更强的配位键有助于lhc的组装，增强lhc的稳定性。Chl a的7-甲基氧化为带负电性的甲酰基，导致四吡咯大环π电子向分子外围重新分布。因此，Chl b中心的Mg比Chl a中心的Mg有更多的正电荷，可以预期它与“硬”的、电负性强的路易斯碱配合得更强。Chl容易与His的咪唑基团或Glu的电荷补偿羧基与Arg的胍基团形成配位键(Eggink, l.l.， and Hoober, J.K. 2000)。叶绿素与含有保留基序的肽序列结合。生物。化学。275:9087 - 9090)。令人惊讶的是,背影b结合肽的水平包含这些配体是远远低于的背影,电负性均衡的考虑,纳等人证明了负电荷的迁移从咪唑金属在配合(Ni)细菌叶绿素(Yerushalmi纳,D, R, Brumfeld, V,阿舒尔,I.， Scheer, H.， Baldridge, K.K.和Scherz, A. 2000。 Optical absorption and computational studies of [Ni]-bacteriochlorophyll-a. New insight into charge distribution between metal and ligands. J. Am. Chem. Soc. 122: 3937-3944). These data suggest that interaction of the more positive Mg center of Chl b with His, and possibly the Glu-Arg pair, is weakened by partial positive charge on these ligands resulting from electron density migration to the metal. Binding of Chl b may also be inhibited by strong interaction with water (Ballschmiter, K., Cotton, T.M., Strain, H.H., and Katz, J.J. 1969. Chlorophyll-water interactions: Hydration, dehydration and hydrates of chlorophyll. Biochim. Biophys. Acta 180: 347-359). We would then expect that Chl b would favor coordination with ligands containing electronegative oxygen, with carboxyl and amide groups most favored to displace a water molecule. This proposal is in general supported by the ligands selected by each of the Chls during assembly of the light-harvesting complex. The stronger Lewis acid property of Chl b possibly facilitates retention of apoproteins of light-harvesting complexes during import into the chloroplast.
澄清协调专用性的附录
J·肯尼斯·胡伯，亚利桑那州立大学植物生物学系
2003年1月15日
Eggink, L.L.， Park, H. and Hoober, J.K. 2001的附录。叶绿素b在光合作用中的作用:假设。植物生物学杂志1:2。
本文提出叶绿素(Chl) a和b在叶绿体类囊体膜的捕光复合物(lhc)中结合的特异性是由于Mg在Chl b中具有较强的Lewis酸性质。Chl b与载脂蛋白之间形成的更强的配位键有助于lhc的组装，增强lhc的稳定性。Chl a的7-甲基氧化为带负电性的甲酰基，导致四吡咯大环π电子向分子外围重新分布。因此，Chl b中心的Mg比Chl a中心的Mg有更多的正电荷，可以预期它与“硬”的、电负性强的路易斯碱配合得更强。Chl容易与His的咪唑基团或Glu的电荷补偿羧基与Arg的胍基团形成配位键(Eggink, l.l.， and Hoober, J.K. 2000)。叶绿素与含有保留基序的肽序列结合。生物。化学。275:9087 - 9090)。令人惊讶的是,背影b结合肽的水平包含这些配体是远远低于的背影,电负性均衡的考虑,纳等人证明了负电荷的迁移从咪唑金属在配合(Ni)细菌叶绿素(Yerushalmi纳,D, R, Brumfeld, V,阿舒尔,I.， Scheer, H.， Baldridge, K.K.和Scherz, A. 2000。 Optical absorption and computational studies of [Ni]-bacteriochlorophyll-a. New insight into charge distribution between metal and ligands. J. Am. Chem. Soc. 122: 3937-3944). These data suggest that interaction of the more positive Mg center of Chl b with His, and possibly the Glu-Arg pair, is weakened by partial positive charge on these ligands resulting from electron density migration to the metal. Binding of Chl b may also be inhibited by strong interaction with water (Ballschmiter, K., Cotton, T.M., Strain, H.H., and Katz, J.J. 1969. Chlorophyll-water interactions: Hydration, dehydration and hydrates of chlorophyll. Biochim. Biophys. Acta 180: 347-359). We would then expect that Chl b would favor coordination with ligands containing electronegative oxygen, with carboxyl and amide groups most favored to displace a water molecule. This proposal is in general supported by the ligands selected by each of the Chls during assembly of the light-harvesting complex. The stronger Lewis acid property of Chl b possibly facilitates retention of apoproteins of light-harvesting complexes during import into the chloroplast.
此外，在这篇论文中，加氧酶被错误地称为“Chl(ide) a氧化酶”。
相互竞争的利益
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