1. Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
2. Laboratório de Planejamento e Desenvolvimento de Fármacos; Instituto de Ciências Exatas e Naturais; Universidade Federal do Pará; CP 11101 Belém PA 66075-110 Brazil
3. School of Chemistry and Physics; University of KwaZulu-Natal; Durban 4001 South Africa
4. Protein Structure-Function Research Unit; School of Molecular and Cell Biology; University of the Witwatersrand; Wits 2050 South Africa