title: Expression of cysteine proteinases by metacyclic promastigotes of Leishmania mexicana.
abstract: The expression of cysteine proteinases by metacyclic promastigotes of Leishmania mexicana was investigated using gelatin polyacrylamide gel electrophoresis. Two prominent bands were detected which distinguished metacyclics from multiplicative promastigotes, lacking detectable cysteine proteinase activity, and amastigotes, with a distinct banding pattern composed of multiple enzymes. A correlation between relative activity of the metacyclic-specific bands and the prevalence of metacyclics was found both during the growth cycle in vitro as metacyclogenesis occurred, and by comparison of stationary phase populations from consecutive subpassages in vitro. Irreversible inhibition of the metacyclic activities using N-benzyloxycarbonyl-phenylalanyl-alanyl diazomethane did not inhibit metacyclic to amastigote transformation in vitro. These activities provide a useful biochemical marker for the metacyclic promastigotes of L. mexicana.
authors.affiliation: Department of Zoology, University of Glasgow, United Kingdom.
authors.forename: P A
authors.initials: PA
authors.lastname: Bates
authors.forename: C D
authors.initials: CD
authors.lastname: Robertson
authors.forename: G H
authors.initials: GH
authors.lastname: Coombs
mesh_terms: D000818:Animals; D003470:Culture Media; D003546:Cysteine Endopeptidases / Q000096:biosynthesis* / Q000737:chemistry / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003978:Diazomethane / Q000031:analogs & derivatives; D006863:Hydrogen-Ion Concentration; D007894:Leishmania mexicana / Q000201:enzymology* / Q000254:growth & development; D008970:Molecular Weight
chemical_list: D003470:Culture Media; D015853:Cysteine Proteinase Inhibitors; D003978:Diazomethane; D003546:Cysteine Endopeptidases