Momordin (protein) explained

Momordin or α-momorcharin is one of several related proteins isolated from several plants of the genus Momordica, which includes the bitter melon (M. charantia) and the balsam apple (M. balsamina).

These enzymes are potent inhibitor of protein synthesis in eukaryotes by inactivating the ribosomes.^{[1] [2] [3]} However its cytotoxic activity is limited because it is not taken up by the cells; it has to be chemically modified to do so.^[4]

There are several variants, including momordin II (from M. balsamina)^{[1] [5]} and momordin-a (from M. charantia).^{[3] [6]}

See also

• Momordin (saponin), an unrelated compound (a saponin of the triterpenoid oleanic acid).

Notes and References

1. Ortigao . M. . Better . M. . Momordin II, a ribosome inactivating protein from Momordica balsamina, is homologous to other plant proteins . Nucleic Acids Research . 20 . 17 . 4662 . 1992 . 1408771 . 334202 . 10.1093/nar/20.17.4662.
2. Husain . J. . Tickle . I. J. . Wood . S. P. . Crystal structure of momordin, a type I ribosome inactivating protein from the seeds of Momordica charantia . FEBS Letters . 342 . 2 . 154–158 . 1994 . 8143869 . 10.1016/0014-5793(94)80491-5. free . 1994FEBSL.342..154H .
3. Minami . Y. . Funatsu . G. . The complete amino acid sequence of momordin-a, a ribosome-inactivating protein from the seeds of bitter gourd (Momordica charantia) . Bioscience, Biotechnology, and Biochemistry . 57 . 7 . 1141–1144 . 1993 . 7763984 . 10.1271/bbb.57.1141.
4. Leamon . C. P. . Low . P. S. . Cytotoxicity of momordin-folate conjugates in cultured human cells . The Journal of Biological Chemistry . 267 . 35 . 24966–24971 . 1992 . 10.1016/S0021-9258(19)73992-1 . free . 1460001.
5. Valbonesi . P. . Barbieri . L. . Bolognesi . A. . Bonora . E. . Polito . L. . Stirpe . F. . Preparation of highly purified momordin II without ribonuclease activity . Life Sciences . 65 . 14 . 1485–1491 . 1999 . 10530800 . 10.1016/s0024-3205(99)00389-6.
6. Minami . Y. . Islam . M. R. . Funatsu . G. . Chemical modifications of momordin-a and luffin-a, ribosome-inactivating proteins from the seeds of Momordica charantia and Luffa cylindrica: Involvement of His140, Tyr165, and Lys231 in the protein-synthesis inhibitory activity . Bioscience, Biotechnology, and Biochemistry . 62 . 5 . 959–964 . 1998 . 9648227 . 10.1271/bbb.62.959. free .