Biochemisry

MaryEllen Henson

September 23, 2015

Topic: Biochemistry

Palma(2015) Brazilian wasp venom kills cancer cells by opening them up; Sao Paulo State University (September 1, 2015) found

http://m.phys.org/news/2015-09-brazilian-wasp-venom-cancer-cells.html

The Brazilian wasps venom is able to kill cancer cells without harming normal cells. The venoms toxin interacts with lipids abnormally placed on cancer cells surface, creating holes that allow the cells vital functions to leak out. The toxin stops microbial pathogens by disrupting the cell membrane. The fact that the toxin can affect cancer cells but not normal cells is thought to be because of the cancers cells unique shape. In healthy cell membranes, phospholipids called phosphatidylserine and phosphatidylethanolamine are located on the inner membrane leaflet facing the inside wall, while in a cancer cell they are embedded in the membrane facing putting cell surroundings.

The theory was tested by making model membranes containing the phospholipids and exposing them to the toxin. The presence of phosphatidylserine increased the binding of the toxin to the membrane. Still, the presence of phosphatidylethanolamine quickly disrupted the membrane, causing the holes to increase in size. "Formed in only seconds, these large pores are big enough to allow critical molecules such as RNA and proteins to easily escape cells" (Neto, 6). In the future, the scientists plan to alter the amino acid sequence in the toxin to make it more selective for clinical purposes.