The enzymic activity of the mammalian pyruvate dehydrogenase complex is regulated by the phosphorylation of three serine residues (sites 1, 2 and 3) located on the E1 component of the complex. Here we report that the four isoenzymes of protein kinase responsible for the phosphorylation and inactivation of pyruvate dehydrogenase (PDK1, PDK2, PDK3 and PDK4) differ in their abilities to phosphoryl...

We examined ventricular myosin isoenzymes in hearts of normal and thyroxine (T,)treated rabbits by polyacrylamide gel electrophoresis using non-dissociating conditions as described by Hoh et al. (1977). The rabbits received daily injections of T4 (150 /ig/kg) or saline and were killed at 1 to 17 days. A myosin-enriched fraction was prepared from each ventricle by extraction in 100 mM pyrophosph...

We have previously shown that stromal and thylakoid-bound ascorbate peroxidase (APX) isoenzymes of spinach chloroplasts arise from a common pre-mRNA by alternative splicing in the C-terminus of the isoenzymes [Ishikawa, Yoshimura, Tamoi, Takeda and Shigeoka (1997) Biochem. J. 328, 795-800]. To explore the production of mature, functional mRNA encoding chloroplast APX isoenzymes, reverse transcr...