Peptidases could hold key to anti-malarial breakthrough

Researchers recently evaluated two enzymes that the malaria parasite uses to chew up hemoglobin as potential targets for anti-malarial drugs.

The research on the enzymes, called peptidases, was conducted by scientists from the University of Pennsylvania, Monash University and Virginia Tech, and appeared online in an early edition of the Proceedings of the National Academy of Science, according to

"The basis for this research was to use small molecule inhibitors to help understand the biology of the malaria parasite and to find new drug targets as drug-resistant parasites necessitate the discovery of new antimalarials," Dr. Doron C. Greenbaum, an assistant professor of pharmacology at Penn, said, reports.

The Plasmodium falciparum parasite causes malaria after it is delivered into a human host through a mosquito bite. It lives in the host’s red blood cells and begins to digest hemoglobin, the protein that carries oxygen.

The scientists are attempting to determine which enzymes are responsible for creating amino acids in the feeding process.

It is thought that two particular enzymes, aminopeptidases, might release single amino acids from peptides, or proteins. It has been difficult, however, to determine for certain whether or not this is the case.

The team was able to inhibit one or the other of the enzymes by using a chemical genetic tool that they called an activity-based probe.

"When we inhibited the parasite enzyme PfA-M1, it blocked hemoglobin degradation, starving the parasite to death," Greenbaum said, according to "While inhibition of the leucyl aminopeptidase showed it to have an important but distinct role earlier in the parasite's life cycle within the red blood cell. Our collective data suggest that these two MAPs are both potential antiparasitic drug targets."