Experimental analysis of origin and phylogeny of chloroplasts in algae

藻类叶绿体起源和系统发育的实验分析

• 批准号: 07044211
• 负责人: MIMURO Mamoru
• 金额: $ 0.96万
• 依托单位: Okazaki National Research Institution
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07044211/
• 关键词: Photosynthesis; Evolution; Chloroplasts; Algae; Symbiosis; Light harvesting complex I; Cytochrome c550

On the origin of chloroplasts, there are two alternative hypotheses ; that is monophyletic and multiphyletic.Based on the gene sequence in chloroplasts, monophyletic hypothesis is rather favorable, however this should be confirmed by other methods.Thus, we investigated the phylogeny of two kinds of polypeptides which are functioning in chloroplasts, (1) antenna pigment-protein complexes and (2) electron transport components.1.Mimuro and Gantt isolated a light harvesting complex I (LHC I) from the red alga Porphyridium cruentum, and characterized the specttoscopic properties.The energy transfer from carotenoid (beta-carotene or zeaxanthin) to chlorophyll alpha was clearly shown for the first time by the low temperature spectra.2.Ikeuchi and Plumley isolated a highly purified photosystem I complex from a diatom Cylindrotheca sp.for the first time and determined the N-terminal sequence of several polypeptides.Among them, they identified psaD and also obtained several new components.3.Presence of cytochrome c55 was investigated in several algal species.This component is known to be present in cyanobacteria and function as a water oxidizing component.Since heme is not necessary for that function, its real function has been controversial.Mimuro and Gantt tried to identify cyt c550 in P.cruentum, however they failed to do in USA.Thus, they again tried in Japan using a highly sensitive photometer, and finally identified cyt c550 together with the other cytochromes (cyt b6, cyt559 and cyt c553).Mimuro and Gantt agreed to analyze the stoichiometry between cyt c550 and photosystem II reaction center near in future.4.Ikeuchi and Plumley started to grow Heterosigma sp, Raphidophyceae, to analyze the diversity of components in photosynthesis.5.We four agreed to continue the research for the next few years by applying again to this program.

关于叶绿体的起源，有两种假说;根据叶绿体中的基因序列，单系假说是比较有利的，但这需要用其他方法来证实。因此，我们研究了两种在叶绿体中起作用的多肽的同源性，（1）触角色素-蛋白质复合物和（2）电子传递组分。1. Mimuro和甘特从红色紫球藻中分离到一种捕光复合物I（LHC I），并对类胡萝卜素的吸光特性进行了表征。（β-胡萝卜素或玉米黄质）2. Ikeuchi和Plumley从一个含有叶绿素a的植物中分离出一个高纯度的光系统I复合物，3.细胞色素c55在几种藻类中的存在情况，该成分存在于蓝藻中，作为水氧化成分，由于血红素不是该功能所必需的，它的真实的功能一直存在争议。Mimuro和甘特试图在P.cruentum中鉴定cyt c550，但在美国未能成功。因此，他们在日本使用高灵敏度光度计再次尝试，最终与其他细胞色素一起鉴定了cyt c550（cyt b6，cyt 559和cyt c553）.Mimuro和甘特同意在未来分析cyt c550和光系统II反应中心之间的化学计量关系. 4. Ikeuchi和Plumley开始培养异弯藻属（Heterosigma sp），针藻科，分析光合作用组分的多样性. 5.我们四人同意在未来几年继续研究，再次申请该计划.

项目成果

Mamoru Mimuro, Shi Tang, katsunori Aizawa and Elisabeth Gantt: "Spectroscopic characteristics of light-harvesting complex I and photosystem I core complex isolated from a red alga, Porphyridium cruentum." FEBS Letters. (in preparation).

Mamoru Mimuro、Shi Tang、katsunori Aizawa 和 Elisabeth Gantt：“从红藻 Porphyridium cruentum 中分离出的光捕获复合物 I 和光系统 I 核心复合物的光谱特征。”

Mamoru Mimuro,Shi Tang,Katsunori Aizawa and Elisabeth Gantt: "Spectroscopic characteristics of light-harvesting complex I and photosystem I core complex isolated from a red alga,Porphyridium cruentum." FEBS Letters. (投稿準備中).

Mamoru Mimuro、Shi Tang、Katsunori Aizawa 和 Elisabeth Gantt：“从红藻 Porphyridium cruentum 中分离出的光捕获复合物 I 和光系统 I 核心复合物的光谱特征（准备提交）。”