TY - JOUR
T1 - Orientation of pigments in the thylakoid membrane and in the isolated chlorophyll-protein complexes of higher plants. I. Determination of optimal conditions for linear dichroism measurement
AU - Haworth, Philip
AU - Arntzen, Charles J.
AU - Tapie, Pierre
AU - Breton, Jacques
N1 - Funding Information:
P.H. and C.J.A. would like to acknowledge financial support in part from NSF Grant No. PCM 7718953 and DOE Contract No. DE-AC02-76ERO-1338 to Michigan State University.
PY - 1982/3/16
Y1 - 1982/3/16
N2 - The nature and possible causes of polarized light-scattering artefacts in linear dichroism measurements are investigated. Using criteria described in this article, the available orientation techniques have been critically assessed in order to obtain the linear dichroism spectra of thylakoids and of pigment-protein complexes isolated from pea. It is demonstrated here that the polyacrylamide gel squeezing technique of Abdourakhmanov et al. (Abdourakhmanov, I.A., Ganago, A.O., Erokhim, Yu.E., Solov'ev, A.A. and Chugunov, V.A. (1979) Biochim. Biophys. Acta 546, 183-186) does not lead to pigment degradation and that the linear dichroism spectra obtained in these conditions are essentially free of scattering artefacts. The linear dichroism spectra of light-harvesting complex isolated in different states of aggregation or incorporated into phospholipid vesicles are compared to the spectra of thylakoids. This comparison indicates: (1) that the isolation procedure of Burke et al. (Burke, J.J., Ditto, C.L. and Arntzen, C.J. (1978) Arch. Biochem. Biophys. 187, 252-263) leads to light-harvesting complex in which the in vivo orientation of pigments is preserved; (2) that the antenna chlorophyll a molecules of this complex have a significant degree of orientation with respect to the plane of the thylakoid.
AB - The nature and possible causes of polarized light-scattering artefacts in linear dichroism measurements are investigated. Using criteria described in this article, the available orientation techniques have been critically assessed in order to obtain the linear dichroism spectra of thylakoids and of pigment-protein complexes isolated from pea. It is demonstrated here that the polyacrylamide gel squeezing technique of Abdourakhmanov et al. (Abdourakhmanov, I.A., Ganago, A.O., Erokhim, Yu.E., Solov'ev, A.A. and Chugunov, V.A. (1979) Biochim. Biophys. Acta 546, 183-186) does not lead to pigment degradation and that the linear dichroism spectra obtained in these conditions are essentially free of scattering artefacts. The linear dichroism spectra of light-harvesting complex isolated in different states of aggregation or incorporated into phospholipid vesicles are compared to the spectra of thylakoids. This comparison indicates: (1) that the isolation procedure of Burke et al. (Burke, J.J., Ditto, C.L. and Arntzen, C.J. (1978) Arch. Biochem. Biophys. 187, 252-263) leads to light-harvesting complex in which the in vivo orientation of pigments is preserved; (2) that the antenna chlorophyll a molecules of this complex have a significant degree of orientation with respect to the plane of the thylakoid.
KW - (Pea chloroplast)
KW - Chlorophyl-protein complex
KW - Linear dichroism
KW - Pigment orientation
KW - Polarized light
KW - Thylakoid membrane
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U2 - 10.1016/0005-2728(82)90164-5
DO - 10.1016/0005-2728(82)90164-5
M3 - Article
AN - SCOPUS:0000426562
SN - 0005-2728
VL - 679
SP - 428
EP - 435
JO - BBA - Bioenergetics
JF - BBA - Bioenergetics
IS - 3
ER -