The presence of long-wavelength chlorophyll a spectral forms in the light-harvesting chlorophyll a/b protein complex II

✍ Scribed by Giuseppe Zucchelli; Robert C. Jennings; Flavio M. Garlaschi

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 898 KB
• Volume: 6
• Category: Article
• ISSN: 1011-1344
• DOI: 10.1016/1011-1344(90)85112-a

✦ Synopsis

Light-harvesting chlorophyll a/b protein complex II, spectra deconvolution, energy transfer, spinach chloroplast.

Room temperature absorption spectra (in the wavelength range 600-740 run) of light-harvesting chlorophyll a/b protein complex II (LHCPII) isolated from spinach and pea have been analysed in terms of a linear combination of asymmetric gaussian bands. All the commonly observed chlorophyll spectra bands are found, including significant levels of the components which peak around 684 and 693 run. The presence of these long-wavelength absorbing forms in LHCPII is also suggested by analysis of the room temperature absorption spectra of thylakoids of the chlorina barley mutant, which lacks LHCPII, and pea grown in intermittent light. Prom a comparative analysis of room temperature and liquid nitrogen temperature absorption spectra of LHCPII, it is concluded that temperature modifies the spectral bands, narrowing the bands up to 677 run and markedly depressing the 684 run band. These observations are not in close agreement with the commonly accepted ideas on the distribution of the chlorophyll spectral species with respect to reaction centres in the photosystem II (PSII) antenna matrix.