Isolation of lipoxygenase isoforms from Glycine max embryo axes based on apparent cross-reactivity with anti-myosin antibodies.

Three lipoxygenase isoforms were isolated from Glycine max embryo axes. A number of proteins around 97 kDa cross-reacted with several anti-actin and anti-myosin antibodies and these were used to follow their purification through gel filtration, hydroxyapatite and anion exchange columns. The 97-kDa cross-reactive material eluted in the unbound fractions of the last anion exchange column, and displayed two components of pI's 6.2 and 6.3. Further phase partition of this fraction in TX-114 yielded a hydrophobic 97 kDa protein. Additionally, a 95-kDa protein was retained and eluted from this last column. Partial peptide sequences indicated that the 95 kDa protein was soybean lipoxygenase-1, the first 97 kDa protein was lypoxygenase-3, and the hydrophobic 97 kDa protein was lipoxygenase-2. Several possible reasons for the cross-reactivity with the antibodies are discussed. To our knowledge, this is the first example of individual lipoxygenase isoforms isolated from soybean embryo axes.