Isolation and characterization of an abortifacient protein,momorcochin, from root tubers of Momordica cochinchinensis (Family Cucurbitaceae)

A glycoprotein with a molecular weight of 32 000 as estimated by SDS-polyacrylamide gel electrophoresis, and characterized by an abundance of Asp and Glu residues and an absence of Cys residues in its amino acid analysis, was isolated from fresh root tubers of Momordica cochinchinensis using a procedure that involved acetone precipitation, ammonium sulfate precipitation, ion exchange chromatography on DEAE Sepharose CL-6B and gel filtration on Sephadex G-75. The protein was capable of inducing mid-term abortion in mice. The characteristics of this protein were compared and contrasted with those of the abortifacient proteins isolated from other plants of the Cucurbitaceae family.