a1 Institut für Biochemie II, Im Neuenheimer Feld 328, D-6900 Heidelberg, FRG
a2 Division of Biochemistry, Bernhard-Nocht-Institut, Bernhard-Nocht-Strasse 74, D-2000 Hamburg 4, FRG
a3 Medical Research Council, Cell Biophysics Unit, King's College, Drury Lane, London WC2
a4 Division of Parasitology, National Institute for Medical Research, Mill Hill, London NW7 1AA
Electrophoresis of extracts of schizonts of Plasmodium knowlesi in non-dissociating polyacrylamide gels, separates several bands of acid endopeptidase activity. A polyclonal antiserum, produced by immunization with purified merozoites, failed to distinguish between different bands of the parasite enzyme, indicating that they are serologically related. Apart from the loss of one minor peak, extraction in Triton X-100 did not reduce the enzyme's electrophoretic heterogeneity. The antiserum did not react with red cell acid proteases.
(Accepted July 26 1985)
* Reprint requests to: Dr R. J. M. Wilson, Division of Parasitology, National Institute for Medical Research, Mill Hill, London NW7 1AA.