CPQ and malaria: A truncated form of the PfA-M1 lacking the unique N-terminal extension (residues 195–1085, correlating with the start of the M1 aminopeptidase of Escherichia coli PepN) was expressed as a functional recombinant form in E. coli and the purified enzyme shown to exhibit physico-biochemical characteristics identical to those of a naturally occurring soluble form of the PfA-M1 enzyme in malaria cells.