Rapid purification of a chloroplast nucleoside diphosphate kinase using CoA-affinity chromatography

An 18 kDa protein from spinach chloroplasts was purified in one step to homogeneity using CoA-affinity chromatography. Its N-terminal sequence was identical to spinach nucleoside diphosphate kinase II (NDPK II). The kinase was isolated as a approximately 100 kDa complex. Immunoblotting detected NDPKII in plastids from leaves, roots, seeds and male flowers. NDPK I, an isoform of NDPK II, was not found in chloroplast soluble extracts, whereas NDPK III was present.