Cathepsin B-like cysteine proteases confer intestinal cysteine protease activity in Haemonchus contortus

S Shompole; D P Jasmer

doi:10.1074/jbc.M007321200

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Cathepsin B-like cysteine proteases confer intestinal cysteine protease activity in Haemonchus contortus

Journal article

Open access

Peer reviewed

Cathepsin B-like cysteine proteases confer intestinal cysteine protease activity in Haemonchus contortus

S Shompole and D P Jasmer

The Journal of biological chemistry, Vol.276(4), pp.2928-2934

01/26/2001

DOI: https://doi.org/10.1074/jbc.M007321200

Handle:

https://hdl.handle.net/2376/105244

PMID: 11032834

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Abstract

Amino Acid Sequence

Haemonchus - enzymology

Helminth Proteins - isolation & purification

Cathepsin B - antagonists & inhibitors

Molecular Sequence Data

Substrate Specificity

Cathepsin B - metabolism

Sequence Homology, Amino Acid

Tissue Distribution

Animals

Chromatography, Affinity

Cathepsins - classification

Helminth Proteins - metabolism

Cathepsin B - isolation & purification

Cathepsins - antagonists & inhibitors

Hydrogen-Ion Concentration

Intestines - enzymology

Cathepsin B-like cysteine protease genes (cbls) constitute large multigene families in parasitic and nonparasitic nematodes. Although expressed in the intestine of some nematodes, the biological and biochemical functions of the CBL proteins remain unresolved. Di- and tetra-oligopeptides were used as fluorogenic substrates and irreversible/competitive inhibitors to establish CBL functions in the intestine of the parasitic nematode Haemonchus contortus. Cysteine protease activity was detected against diverse substrates including the cathepsin B/L substrate FR, the caspase 1 substrate YVAD, the cathepsin B substrate RR, but not the CED-3 (caspase 3) substrate DEVD. The pH at which maximum activity was detected varied according to substrate and ranged from pH 5.0 to 7.0. Individual CBLs were affinity isolated using FA and YVAD substrates. pH influenced CBL affinity isolation in a substrate-specific manner that paralleled pH effects on individual substrates. N-terminal sequencing identified two isolated CBLs as H. contortus GCP-7 (33 kDa) and AC-4 (37 kDa). N termini of each began at a position consistent with proregion cleavage and protease activation. Isolation of the GCP-7 band by each peptide was preferentially inhibited when competed with a diazomethane-conjugated inhibitor, Z-FA-CHN(2), demonstrating one functional difference among CBLs and among inhibitors. Substrate-based histological analysis placed CBLs on the intestinal microvilli. Data indicate that CBLs are responsible for cysteine protease activity described from H. contortus intestine. Results also support a role of CBLs in nutrient digestion.

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Title: Cathepsin B-like cysteine proteases confer intestinal cysteine protease activity in Haemonchus contortus
Creators: S Shompole - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164-7040, USA. shompole@vetmed.wsu.edu
D P Jasmer
Publication Details: The Journal of biological chemistry, Vol.276(4), pp.2928-2934
Academic Unit: Veterinary Microbiology and Pathology, Department of
Publisher: United States
Identifiers: 99900546966101842
Language: English
Resource Type: Journal article