Construction of an array of photosensitizers within a ring-shaped hemoprotein assembly toward a light harvesting system

2015 Fiscal Year Final Research Report

• Project/Area Number: 25810099
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Bio-related chemistry
• Research Institution: Osaka University
• Principal Investigator: Oohora Koji 大阪大学, 工学(系)研究科(研究院), 助教 (10631202)
• Research Collaborator: HAYASHI Takashi ; MAHISMA Tsuyoshi
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 光捕集 / ヘムタンパク質 / 超分子 / 光増感剤

Outline of Final Research Achievements

A hexameric tyrosine-coordinated heme protein (HTHP) containing photosensitizer molecules was prepared in an effort to construct a biomolecule with engineered photochemical properties. Zn protoporphyrin IX (ZnPP) and Zn chlorin e6 (ZnCe6) are inserted into the apoprotein of HTHP to yield reconstituted proteins which maintain the original hexameric structure of HTHP. The fluorescence quenching efficiencies provided by methyl viologen as an electron acceptor for the completely reconstituted proteins with ZnPP and ZnCe6 are 2.3 and 2.6 fold-higher than that of the corresponding partially photosensitizer-inserted proteins, respectively. This indicates that energy migration occurs among the photosensitizers bound within the protein matrices. These findings are expected to lead to development of new protein-based artificial light harvesting systems to demonstrate the light-driven energy conversion.

Free Research Field

生体関連化学