Fasciola hepatica: a secreted cathepsin L-like proteinase cleaves host immunoglobulin.
Adult Fasciola hepatica secrete a cysteine proteinase capable of cleaving host IgG close to the papain cleaving site. The proteinase was separated by size permeation chromatography. Gelatin-substrate polyacrylamide gel electrophoresis analysis revealed that the proteinase migrates as 6 proteolytic bands in the apparent molecular size range 60-90 kDa. Based on pH profiles of activity, inhibition studies using diethylpyrocarbonate and the diazomethylketone Z-phe-ala-CHN2, and characterising the substrate specificity of the enzymes using fluorogenic peptide substrates we have shown that the 60-90-kDa proteinases are cathepsin L-like proteinases.
Smith
A M
AM
School of Biological Sciences, Dublin City University, Republic of Ireland.
Dowd
A J
AJ
Heffernan
M
M
Robertson
C D
CD
Dalton
J P
JP
D000818:Animals; D056668:Cathepsin L; D002403:Cathepsins / Q000378:metabolism*; D002417:Cattle; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D010450:Endopeptidases; D005210:Fasciola hepatica / Q000201:enzymology*; D007074:Immunoglobulin G / Q000378:metabolism*
D015853:Cysteine Proteinase Inhibitors; D007074:Immunoglobulin G; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D056668:Cathepsin L