Purification and Some Molecular Properties of Rice Germ Calmodulin

Abstract

Calmodulin (CaM) from rice germ (Oryza sativa L) was purified to homogeneity by hydrophobic interaction chromatography and gel filtration. The protein showed a single spot by SDS-PAGE. This purified protein had multiple absorption maxima at 276~279, 268, 265, 258, and 253 nm. Like other plant CaM, the protein contained one mole of Tm₃Lys, cysteine, and tyrosine, and tryptophan was not detected. Hydrophobic properties of rice germ, spinach, and Neurospora crassa CaM were directly tested by an HPLC method using an ODS-120T column and by a hydropathy plotting method. Obvious hydrophobic differences with rice germ CaM>spinach CaM>N. crassa CaM, were observed among calmodulins from rice germ and others.

• calmodulin
• calcium binding
• conformational change
• hydrophobicity
• EF-hand protein