Abstract
A stable, soluble, and photoactive protochlorophyll(ide) complex has been extracted from dark-grown barley (Hordeum vulgare L.) leaves with buffer containing saponin and glycerol. After ammonium sulfate precipitation, the redissolved pigment complex was partially purified by chromatography on Sephadex gels in the presence of saponin. With the assumptions that the pigment complex from barley has the same shape and density as the proteins used for calibration, its molecular weight is 63,000. Photoactive protochlorophyll(ide) complex isolated from bean (Phaseolus vulgaris L.) and chromatographed by the same procedures has an aparent molecular weight of 100,000 or greater. No chromatographic separation of photoactive and inactive protochlorophyll(ide) complexes was observed. Photoconversion of protochlorophyll(ide) to chlorophyll(ide) did not change the chromatographic behavior of the pigment complex.
The protochlorophyll(ide) complex had an absorption maximum at 644 nanometers and a corresponding fluorescence emission maximum at 652 nanometers. Photoconversion yielded chlorophyll(ide) complex with an absorption maximum at 678 nanometers and a main fluorescence emission maximum at 685 nanometers. Spectrofluorometry on partially photoconverted preparations gave no indication of energy transfer from protochlorophyll(ide) to chlorophyll(ide). This result is consistent with the presence of a single protochlorophyll(ide) molecule per active unit of the pigment complex.
It is concluded that the protochlorophyll(ide) complex obtained from barley represents an active subunit of protochlorophyll holochrome.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BOARDMAN N. K. Studies on a protochlorophyll-protein complex. I. Purification and molecular-weight determination. Biochim Biophys Acta. 1962 Jul 30;62:63–79. doi: 10.1016/0006-3002(62)90492-4. [DOI] [PubMed] [Google Scholar]
- BOARDMAN N. K. Studies on a protochlorophyll-protein complex. II. The photo-conversion of protochlorophyll to chlorophyll alpha in the isolated complex. Biochim Biophys Acta. 1962 Oct 22;64:279–293. doi: 10.1016/0006-3002(62)90737-0. [DOI] [PubMed] [Google Scholar]
- Butler W. L., Briggs W. R. The relation between structure and pigments during the first stages of proplastid greening. Biochim Biophys Acta. 1966 Jan 4;112(1):45–53. doi: 10.1016/s0926-6585(96)90006-0. [DOI] [PubMed] [Google Scholar]
- Henningsen K. W. Macromolecular physiology of plastids. VI. Changes in membrane structure associated with shifts in the absorption maxima of the chlorophyllous pigments. J Cell Sci. 1970 Nov;7(3):587–621. doi: 10.1242/jcs.7.3.587. [DOI] [PubMed] [Google Scholar]
- KRANOVSKII A. A., KOSOBUTSKAIA L. M. Spektral'noe issledovanie sostoianiia khlorofilla pri ego obrazovanii v rastenii i v kolloidnykh rastvorakh veshchestva etiolirovannykh list'ev. Dokl Akad Nauk SSSR. 1952 Jul 1;85(1):177–180. [PubMed] [Google Scholar]
- Kahn A., Boardman N. K., Thorne S. W. Energy transfer between protochlorophyllide molecules: evidence for multiple chromophores in the photoactive protochlorophyllide-protein complex vivo and in vitro. J Mol Biol. 1970 Feb 28;48(1):85–101. doi: 10.1016/0022-2836(70)90220-2. [DOI] [PubMed] [Google Scholar]
- Kahn A. Developmental Physiology of Bean Leaf Plastids II. Negative Contrast Electron Microscopy of Tubular Membranes in Prolamellar Bodies. Plant Physiol. 1968 Nov;43(11):1769–1780. doi: 10.1104/pp.43.11.1769. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kahn A. Developmental Physiology of Bean Leaf Plastids III. Tube Transformation and Protochlorophyll (ide) Photoconversion by a Flash Irradiation. Plant Physiol. 1968 Nov;43(11):1781–1785. doi: 10.1104/pp.43.11.1781. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schopfer P., Siegelman H. W. Purification of protochlorophyllide holochrome. Plant Physiol. 1968 Jun;43(6):990–996. doi: 10.1104/pp.43.6.990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith J. H., Benitez A. The Effect of Temperature on the Conversion of Protochlorophyll to Chlorophyll a in Etiolated Barley Leaves. Plant Physiol. 1954 Mar;29(2):135–143. doi: 10.1104/pp.29.2.135. [DOI] [PMC free article] [PubMed] [Google Scholar]