A Conjugate Composed of Nerve Growth Factor Coupled to a Non-toxic Derivative of Clostridium botulinum Neurotoxin Type A can Inhibit Neurotransmitter Release in Vitro

Abstract

Nerve growth factor (NGF) receptor binding, internalisation and transportation of NGF has been identified as a potential route of delivery for other molecules. A derivative of Clostridium botulinum neurotoxin type A (LH_N) that retains catalytic activity but has significantly reduced cell-binding capability has been prepared and chemically coupled to NGF. Intact clostridial neurotoxins potently inhibit neurotransmitter release at the neuromuscular junction by proteolysis of specific components of the vesicle docking/fusion complex. Here we report that the NGF-LH_N/A conjugate, when applied to PC12 cells, significantly inhibited neurotransmitter release and cleaved the type A toxin substrate. This work represents the successful use of NGF as a targeting moiety for the delivery of a neurotoxin fragment.

Key Words:

• Botulinum toxin type A
• nerve growth factor
• PC12 cells
• synaptosomal-associated protein 25