隐藻藻胆蛋白的结构与能量传递功能

The Structure and Energy Transfer of Phycobiliproteins in Cryptophytic Algae

藻胆蛋白主要存在于蓝藻、红藻及部分隐藻,作为主要的捕光复合物担负着吸收和传递光能的作用。同时藻胆蛋白还是具有很高量子产率的荧光蛋白,因而在光合理论研究及应用方面受到广泛的关注。隐藻藻胆蛋白继承自红藻,但在其蛋白和色基结构、组成、性质、在叶绿体中的存在状态以及与光合膜上反应中心的接触方式等方面都与红、蓝藻藻胆蛋白不同。目前对于红、蓝藻中的藻胆蛋白以及组装而成的藻胆体等均有相当透彻的研究,而对于隐藻藻胆蛋白的了解要少得多。隐藻藻胆蛋白在进化上可能属于比较原始的类型,并且结构上相对于庞大的藻胆体简单得多,因此对于了解藻胆蛋白基本的结构与捕光功能的关系、探讨隐藻的进化地位以及光合生物进化的亲缘关系等的研究方面,具有重要意义,也更为便捷。本文从结构和能量传递功能等方面对目前发现的隐藻藻胆蛋白的研究近况做了综述,总结了目前研究存在的不明之处,并对今后的研究思路提出了看法。

Phycobiliproteins are mainly found in blue-green algae, red algae and some species of cryptophytic algae. They function as major light-harvesting complexes to harvest and transfer sunlight energy. Meanwhile,phycobiliproteins are also fluorescent proteins with high fluorescence quantum yield, and in consequence be widely concerned in both theoretical photosynthesis investigation and application. The cryptophytic phycobiliproteins are inherited from red algae but varied in several ways compared to phycobiliproteins from red algae and blue-green algae, including their protein and phycobilin structure, composition, properties, existential states within chloroplast, as well as the contact forms with reaction centers embedded in photosynthetic membrane,etc. At present, there is a thorough understanding with both phycobiliproteins and phycobilisome assembled by phycobiliproteins in red and blue algae, however, much less understanding about cryptophytic phycobiliproteins.This is considered as the weak point of the study among phycobiliprotein family members. Cryptophytic phycobiliproteins, which are very likely belong to a more primitive type of phycobiliproteins in the view of evolution, and are simpler than that of phycobilisome in terms of structure, therefore, are more important and more convenient in investigating the relation between fundamental structure and light-harvesting function of phycobiliproteins, discussing the evolutionary position of cryptophytic algae and the genetic relationship of photosynthetic organisms etc. In this paper, present research status in the respect of structure, function of energy transfer of cryptophytic phycobiliproteins currently found are reviewed, the current research of the unknown is summarized, and the new ideas for future investigation are also provided.