Purification and characterisation of a novel cysteine conjugate beta-lyasefrom the tapeworm Moniezia expansa

The paper presents the first report of the purification of an invertebrate cysteine conjugate beta-lyase (CCBL). CCBL activity was shown to predominat e within the cytosolic fraction of tissue from the tapeworm Moniezia expans a. The monomeric cytosolic enzyme was isolated with a M-r of 72 kDa and co- purified with transaminase activity towards L-aspartate. The substrate prof ile for M. expansa CCBL is different from that of mammalian CCBLs. Exploiti ng the differences in mammalian and parasite substrate profiles will facili tate the development of helminth targeted conjugates which will not be acti vated by host (mammalian) CCBLs. (C) 2000 Australian Society for Parasitolo gy Inc. Published by Elsevier Science Ltd. All rights reserved.