4.4 Article

Oxidative modification of LHC II associated with photosystem II and PS I-LHC I-LHC II membranes

期刊

PHOTOSYNTHESIS RESEARCH
卷 -, 期 -, 页码 -

出版社

SPRINGER
DOI: 10.1007/s11120-022-00902-1

关键词

Photosystem I; Photosystem II; LHC II; Lhcb1; Lhcb2; Tandem mass spectrometry; Reactive oxygen species (ROS); Spinach; O-1(2)

资金

  1. United States Department of Energy, Office of Basic Energy Sciences [DE-FG02-09ER20310]

向作者/读者索取更多资源

Under aerobic conditions, both photosystems and cytochrome complexes in photosynthetic organisms generate Reactive Oxygen Species (ROS). This study identifies the distribution of oxidatively modified amino acid residues in chlorophyll light-harvesting complexes and highlights differences between complexes from different sources.
Under aerobic conditions the production of Reactive Oxygen Species (ROS) by electron transport chains is unavoidable, and occurs in both autotrophic and heterotrophic organisms. In photosynthetic organisms both Photosystem II (PS II) and Photosystem I (PS I), in addition to the cytochrome b(6)/f complex, are demonstrated sources of ROS. All of these membrane protein complexes exhibit oxidative damage when isolated from field-grown plant material. An additional possible source of ROS in PS I and PS II is the distal, chlorophyll-containing light-harvesting array LHC II, which is present in both photosystems. These serve as possible sources of O-1(2) produced by the interaction of O-3(2) with (3)chl* produced by intersystem crossing. We have hypothesized that amino acid residues close to the sites of ROS generation will be more susceptible to oxidative modification than distant residues. In this study, we have identified oxidized amino acid residues in a subset of the spinach LHC II proteins (Lhcb1 and Lhcb2) that were associated with either PS II membranes (i.e. BBYs) or PS I-LHC I-LHC II membranes, both of which were isolated from field-grown spinach. We identified oxidatively modified residues by high-resolution tandem mass spectrometry. Interestingly, two different patterns of oxidative modification were evident for the Lhcb1 and Lhcb2 proteins from these different sources. In the LHC II associated with PS II membranes, oxidized residues were identified to be located on the stromal surface of Lhcb1 and, to a much lesser extent, Lhcb2. Relatively few oxidized residues were identified as buried in the hydrophobic core of these proteins. The LHC II associated with PS I-LHC I-LHC II membranes, however, exhibited fewer surface-oxidized residues but, rather a large number of oxidative modifications buried in the hydrophobic core regions of both Lhcb1 and Lhcb2, adjacent to the chlorophyll prosthetic groups. These results appear to indicate that ROS, specifically O-1(2), can modify the Lhcb proteins associated with both photosystems and that the LHC II associated with PS II membranes represent a different population from the LHC II associated with PS I-LHC I-LHC II membranes.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.4
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据