Aminopeptidases from Plasmodium falciparum, Plasmodium chabaudi chabaudi and Plasmodium berghei.
Using fluorogenic substrates and polyacrylamide gels we detected in cell-free extracts of Plasmodium falciparum, Plasmodium chabaudi chabaudi and Plasmodium berghei only a single aminopeptidase. A comparative study of the aminopeptidase activity in each extract revealed that the enzymes have similar specificities and kinetics, a near-neutral pH optima of 7.2 and are moderately thermophilic. Each has an apparent molecular weight of 80,000 +/- 10,000, determined by high performance liquid chromatography on a calibrated SW500 column. Whilst the P. c. chabaudi and P. berghei activity co-migrate in native polyacrylamide gels, that of P. falciparum migrates more slowly. The three enzymes can be selectively inhibited by ortho-phenanthroline and are thus metallo-aminopeptidases; however, in contrast to other aminopeptidases the metal co-factor does not appear to be Zn2+.
Curley
G P
GP
School of Biological Sciences, Dublin City University, Glasnevin, Republic of Ireland.
O'Donovan
S M
SM
McNally
J
J
Mullally
M
M
O'Hara
H
H
Troy
A
A
O'Callaghan
S A
SA
Dalton
J P
JP
D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D008666:Metalloendopeptidases / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D010962:Plasmodium berghei / Q000201:enzymology*; D016788:Plasmodium chabaudi / Q000201:enzymology*; D010963:Plasmodium falciparum / Q000201:enzymology*; D013045:Species Specificity
D000626:Aminopeptidases; D008666:Metalloendopeptidases