Work

Separate photosensitizers mediate degradation of the 32-kDa photosystem II reaction center protein in the visible and UV spectral regions.

Year: 1989

Type: article

Abstract: A component of the photosystem II reaction center, the 32-kDa protein, is rapidly turned over in the light. The mechanism of its light-dependent metabolism is largely unknown. We quantified the rate of 32-kDa protein degradation over a broad spectral range (UV, visible, and far red). The quantum yield for degradation was highest in the UVB (280-320 nm) region. Spectral evidence demonstrates two distinctly different photosensitizers for 32-kDa protein degradation. The data implicate the bulk photosynthetic pigments (primarily chlorophyll) in the visible and far red regions, and plastoquinone (in one or more of its redox states) in the UV region. A significant portion of 32-kDa protein degradation in sunlight is attributed to UVB irradiance.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.86.17.6617

Authors: B M Greenberg, V Gaba, O Canaani, S Malkin, A K Mattoo, M Edelman

Institution: Weizmann Institute of Science

Language: English

Topic: Photosynthetic Processes and Mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences

Award: G3391035409