Figure 6.

Biochemical Function of Recombinant ZmOCD1.

(A) Partial pathway for oxalate degradation. The first two steps of oxalate degradation are proposed to be catalyzed by O7 and ZmOCD1.

(B) and (C) In vitro enzyme activity analysis. Purified recombinant ZmOCD1 (B) or the empty vector control (C) was incubated with oxalyl-CoA and the cofactors.

(D) and (E) In vivo enzyme activity analysis. 20-DAP endosperm extracts of the wild type (D) or ocd1-1 (E) were incubated with oxalyl-CoA and the cofactors.

Product formation was analyzed by LC-MS/MS. The relative intensities of the LC-MS/MS transitions of oxalyl-CoA (m/z⁺ = 840.1, red line) and formyl-CoA (m/z⁺ = 796.1, blue line) are shown. The LC-MS/MS analyses were performed under the positive mode (M/H)⁺.