Protein and chlorophyll in photosystem II probed by infrared spectroscopy.

摘要: Abstract The infrared spectra of photosystem II (PS II) enriched submembrane fractions isolated from spinach are obtained in water and heavy suspension Other after a photooxidation reaction was performed on PS to bleach the pigments. bands removed by computer subtr amide (A, B, I, II, III) protein identified. Computer enhancement techniques used narrow bandwidth that weak chlorophyll bands, buried much stronger can be observed. Comparing native photooxidized pr water, we determine three polypeptide domains present material. first domain, which contains 22% th is situated peripheral region system. polypeptides this unfolded devoid chlorophyll. second domain con polypeptides, more organized, chlorophylls. third has an α-helix configuration, does not contain chlorophyll, affected or proton/deuteron exchange. Three different types organisation identified: two have carbonyl groups non-bonded, differing one another only their hydrophobic milieux; weakly bonded unidentified group. Oth but could observed because absorption I band.