Figure 1.

Isoforms of MIPS are differentially expressed during root development. A, Western-blot analyses of bean root proteins during development detected five cross-reacting proteins including the 80-, 56-, and 33-kD proteins previously characterized (Johnson and Wang, 1996). Antigen capture immunoassays (Weiler et al., 1960), ammonium sulfate fractionations, and enzyme assays suggest these proteins are isoforms of MIPS. Each lane contains total proteins (50 μg). B, MIPS was partially purified from roots harvested 8 d after germination. Ammonium sulfate precipitates of 45%, 60%, 70%, and 90% produced 27, 64, 42, and 56 nmol inositol phosphate h^-1 mg^-1 protein, respectively.