Effect of protease class-specific inhibitors on in vitro development of the third- to fourth-stage larvae of Ascaris suum.
Third-stage larvae (L3) of Ascaris suum develop and molt to fourth-stage larvae (L4) during in vitro cultivation; consistently greater than 80% of the larvae develop to L4 during 7 days in culture (DIC). To assess the role of proteases in this process, the effect of protease class-specific inhibitors was studied. The presence of either a serine protease inhibitor (AEBSF, 100 microM) or an aspartic protease inhibitor (pepstatin A, 100 microM) had no effect on the percentage of L4 after 7 DIC. However, the presence of either a cysteine protease inhibitor (Z-Phe-Ala-FMK, 100 microM) or an aminopeptidase inhibitor (amastatin, 100 microM) resulted in 77% and 34% reductions, respectively, in the percentage of L4 compared to untreated cultures; viability of the larvae was not affected. The effect of Z-Phe-Ala-FMK on molting was time and dose dependent. In contrast to Z-Phe-Ala-FMK, E-64, another specific inhibitor of cysteine proteases, had no effect on molting. The data support a role for an aminopeptidase and suggest a role for a cysteine protease in the development of the L3 to L4 stage of A. suum.
Rhoads
M L
ML
Livestock and Poultry Sciences Institute, United States Department of Agriculture, Agricultural Research Service, Beltsville, Maryland 20705, USA.
Fetterer
R H
RH
Urban
J F
JF
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017165:Ascaris suum / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D004396:Coloring Agents / Q000737:chemistry; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007659:Ketones / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D009068:Movement / Q000187:drug effects; D010436:Pepstatins / Q000494:pharmacology; D010455:Peptides; D011480:Protease Inhibitors / Q000494:pharmacology*; D013450:Sulfones / Q000494:pharmacology; D013552:Swine; D013778:Tetrazolium Salts / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry; D014361:Trypsin Inhibitors / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D004396:Coloring Agents; D015853:Cysteine Proteinase Inhibitors; D004151:Dipeptides; D007659:Ketones; D010436:Pepstatins; D010455:Peptides; D011480:Protease Inhibitors; D013450:Sulfones; D013778:Tetrazolium Salts; D013844:Thiazoles; D014361:Trypsin Inhibitors; C014195:Streptomyces pepsin inhibitor; C057383:MDL 201053; C002010:4-(2-aminoethyl)benzenesulfonylfluoride; C016977:amastatin; C022616:thiazolyl blue; C031375:pepstatin