Abstract
The copper protein plastocyanin has been found to be an essential component of the photosynthetic electron transport chain of Chlamydomonas reinhardi, and in this paper we describe a method for its isolation and purification from the wild-type strain. In addition, we describe some of its properties and compare them with those reported for spinach plastocyanin.
The plastocyanin was extracted from acetone powders prepared from intact cells, and it was purified by ion exchange chromatography on DEAE cellulose and gel filtration on Sephadex G-75. The yield of the purified protein ranged from plastocyanin equivalent to 2.0 to 2.5 μg atoms copper per 1000 μmoles chlorophyll. In general the absorption spectrum of plastocyanin from C. reinhardi resembled that of the plastocyanin from spinach. Some spectral differences were found in the ultraviolet region where, in contrast to spinach plastocyanin, that of C. reinhardi had a greater absorbance (relative to peaks in the visible) and less evidence for phenylalanine fine structure. The normal oxidation-reduction potential of C. reinhardi plastocyanin was found to be + 0.37 volts, the same as reported for spinach plastocyanin. The molecular weight of C. reinhardi plastocyanin has been estimated to be 13,000 ± 2000. In contrast, the value for spinach plastocyanin has been found to be 21,000.
Full text
PDF![1637](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bec2/550586/4fe18d8c47a8/plntphys00401-0082.png)
![1638](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bec2/550586/1858122cf8ce/plntphys00401-0083.png)
![1639](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bec2/550586/94b459e3514e/plntphys00401-0084.png)
![1640](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bec2/550586/6a1acb82e67d/plntphys00401-0085.png)
![1641](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bec2/550586/5a17c35bd92a/plntphys00401-0086.png)
![1642](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bec2/550586/a510606735a0/plntphys00401-0087.png)
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Andrews P. Estimation of the molecular weights of proteins by Sephadex gel-filtration. Biochem J. 1964 May;91(2):222–233. doi: 10.1042/bj0910222. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DAVENPORT H. E., HILL R. The preparation and some properties of cytochrome f. Proc R Soc Lond B Biol Sci. 1952 Apr 24;139(896):327–345. doi: 10.1098/rspb.1952.0016. [DOI] [PubMed] [Google Scholar]
- KATOH S. A new copper protein from Chlorella ellisoidea. Nature. 1960 May 14;186:533–534. [PubMed] [Google Scholar]
- SAN PIETRO A., LANG H. M. Photosynthetic pyridine nucleotide reductase. I. Partial purification and properties of the enzyme from spinach. J Biol Chem. 1958 Mar;231(1):211–229. [PubMed] [Google Scholar]