© 1987 Oxford University Press
RESEARCH-ARTICLE |
Immunologically Distinct Forms of Adenylate Kinase in Leaves: Comparison of Subunit Size of Adenylate Kinase from C3 and C4 Plants1
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Kleczkowski, L. A. and Randall, D. D. 1987. Immunologically distinct forms of adenylate kinase in leaves: comparison of subunit size of adenylate kinase from C3 and C4 plants.—J. exp. Bot. 38: 1440–1445.
Antibodies prepared against maize leaf adenylate kinase (E.C. 2.7.4.3 [EC] ) cross-reacted with the enzyme isolated from leaves of both C3 and C4 plants. The immunoreaction was very specific as judged by the presence of a single band on Western immunoblots containing proteins from leaf extracts of several species. The molecular weight (M1) of adenylate kinase determined by means of the immunoblotting was 29 kD and 27 kD for C4 and C3 species, respectively. For both C3 and C4 plants, the antibodies failed to precipitate all adenylate kinase activity in leaf extracts, while they were 100% effective in pelleting the enzyme from maize mesophyll chloroplasts. This indicated the presence of at least two immunologically distinct forms of adenylate kinase in leaves.
It is suggested that the observed differences in molecular structure (M1s) of adenylate kinase from C3 and C4 species might be responsible for distinct catalytic and functional properties of the enzyme in these two groups of plants. The irrununologically-determined occurrence of distinct pools of adenylate kinase in leaves supports previous evidence obtained by means of subcellular fractionation studies.