Structural analysis of toxic volkensin, a type 2 ribosome inactivating protein from Adenia volkensii Harm (kilyambiti plant): Molecular modeling and surface analysis by computational methods and limited proteolysis

Volkensin, isolated from Adenia volkensii, is one of the most toxic type 2 ribosome-inactivating protein (RIP), exerting its biological function by inhibiting protein synthesis. Despite the high sequence identity with type 2 RIPs, including ricin, volkensin shows interesting peculiar properties. In this work a computational model building of volkensin was performed. The volkensin electrostatic potential charge distribution, the hydrophobic profile and the surface topology analyses were also carried out to aid the understanding of structure-function relationships of this potent toxin. Volkensin surface topology was probed by applying a limited proteolysis approach with the aim to gain insights into volkensin conformational features. (C) 2009 Elsevier B.V. All rights reserved.