Abstract
The glutamine synthetase (GS) isozymes in the plant fraction of nodule extracts from 62 cultivars of Phaseolus vulgaris L. and one cultivar of Phaseolus lunatus L. were analyzed by polyacrylamide gel electrophoresis. All P. vulgaris nodule extracts displayed two GS activity bands: a nodule-specific band (GSn1) and a band (GSn2) similar to the single band (GSr) present in root extracts. In nodule extracts of P. lunatus, the GSn1 band was detected, but the GSn2 band was barely detectable. In contrast to P. vulgaris, the GSn2 band and the GSr band of P. lunatus appeared to be different. The electrophoretic mobility of the GSn1 band in P. vulgaris was governed by both the plant cultivar and the development stage of the nodule. In nodule extracts of P. vulgaris and P. lunatus, the zone of GSn1 activity coincided with six to nine distinct protein bands as revealed after treatment of gels, which had previously been stained for GS activity, with Coomassie blue. All these protein bands were shown to consist of polypeptides of identical molecular weight (approximately 47,000 daltons) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our results indicate that P. vulgaris continuously generates isozymes of GSn1 of increasing electrophoretic mobility during the course of nodule development.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
- DAVIS B. J. DISC ELECTROPHORESIS. II. METHOD AND APPLICATION TO HUMAN SERUM PROTEINS. Ann N Y Acad Sci. 1964 Dec 28;121:404–427. doi: 10.1111/j.1749-6632.1964.tb14213.x. [DOI] [PubMed] [Google Scholar]
- Hirel B., Weatherley C., Cretin C., Bergounioux C., Gadal P. Multiple Subunit Composition of Chloroplastic Glutamine Synthetase of Nicotiana tabacum L. Plant Physiol. 1984 Feb;74(2):448–450. doi: 10.1104/pp.74.2.448. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Lara M., Porta H., Padilla J., Folch J., Sánchez F. Heterogeneity of Glutamine Synthetase Polypeptides in Phaseolus vulgaris L. Plant Physiol. 1984 Dec;76(4):1019–1023. doi: 10.1104/pp.76.4.1019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Manhart J. R., Wong P. P. Nitrate reductase activities of rhizobia and the correlation between nitrate reduction and nitrogen fixation. Can J Microbiol. 1979 Oct;25(10):1169–1174. doi: 10.1139/m79-181. [DOI] [PubMed] [Google Scholar]
- McNally S. F., Hirel B., Gadal P., Mann A. F., Stewart G. R. Glutamine Synthetases of Higher Plants : Evidence for a Specific Isoform Content Related to Their Possible Physiological Role and Their Compartmentation within the Leaf. Plant Physiol. 1983 May;72(1):22–25. doi: 10.1104/pp.72.1.22. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McParland R. H., Guevara J. G., Becker R. R., Evans H. J. The purification and properties of the glutamine synthetase from the cytosol of Soya-bean root nodules. Biochem J. 1976 Mar 1;153(3):597–606. doi: 10.1042/bj1530597. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meeks J. C., Wolk C. P., Schilling N., Shaffer P. W. Initial Organic Products of Fixation of [N]Dinitrogen by Root Nodules of Soybean (Glycine max). Plant Physiol. 1978 Jun;61(6):980–983. doi: 10.1104/pp.61.6.980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Palacios R. Neurospora crassa glutamine synthetase. Purification by affinity chromatography and characterization of subunit structure. J Biol Chem. 1976 Aug 10;251(15):4787–4791. [PubMed] [Google Scholar]