June 17, 2008

New Enzyme Might Fight Dysentery, Malaria

U.S. medical researchers say they might have discovered a new enzyme that the dysentery parasite uses to help evade the human immune system.

Every year, about 500 million people worldwide are infected with the parasite that causes dysentery, a global infectious disease second only to malaria.

Johns Hopkins University researchers said the enzyme they discovered might be the first identified that appears as if it could mediate immune system evasion.

The EhROM1 enzyme is part of an ancient group of enzymes known as rhomboid enzymes, the researchers said. In most animals, rhomboid enzymes seem to play a role in cell-to-cell communication, but a couple of years ago Johns Hopkins Assistant Professor Sin Urban found malaria parasites use rhomboid enzymes for a more sinister purpose -- to enter host cells uninvited.

Urban said the EhROM1 enzyme is remarkably similar to those found in malaria parasites, suggesting any potential drugs targeting EhROM1 might be able to treat both dysentery and malaria -- two of the world's most prevalent diseases.

The research that included Rosanna Baker of Hopkins and Leigh Baxt and Upinder Singh of Stanford University appears in the journal Genes & Development.