Bacillus Thuringiensis Cry Proteins: The Status of Their Therapeutic Potential in Infectious Diseases| Biomed Grid

Bacillus thuringiensis Cry proteins has been the subject of intense research in the last three decades. Cry proteins are highly specific towards different orders of insects [1,2] . Bt Cry proteins are a multigenic family. It can be distinguished two main families: Cyt (cytolitic) and Cry (Crystal) protein [1,2] . The protoxins or inmature proteins weights 130 kDa. To be active, protoxins should be processed by the C-terminal region, producing the fragment toxic of 60-70 kDa. The three-dimensional structure of the Cry1Aa, Cry3A toxins has been dilucidated [1,2] . In general Cry toxins are formed by three domains [1,2] . Domain I, formed by a bundle of alpha –seven helix, domain II or the binding domain formed by antiparallel beta-sheet and the domain III formed also by a sandwich of beta-pledged sheets [3,4] By another hand, it has been described the immunogenic and adjuvants properties of the protoxin Cry1Ac [5,6] . The study has been extended to other members of the Cry family, like the protoxins Cry1Aa, Cry1Ab, Cry3A as well as to the Cry1A a, Cry1Ab and Cry3A toxins [7].