Detection of peptidases inTrypanosoma cruziepimastigotes using chromogenic and fluorogenic substrates
| Autor: | Lesley Drake, E. Shaw, H. Enahoro, Frank Ashall, Helen Roberts, Niamh Healy, Stephen Greig |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Trypanosoma cruzi
medicine.medical_treatment Molecular Sequence Data Biology Aminopeptidases Aminopeptidase Substrate Specificity Cathepsin L chemistry.chemical_compound Coumarins Hydrolase medicine Animals Protease Inhibitors Amino Acid Sequence Fluorescent Dyes chemistry.chemical_classification Protease Hydrolysis Dipeptides Hydrogen-Ion Concentration Molecular biology Infectious Diseases Enzyme Digitonin Chromogenic Compounds chemistry Biochemistry biology.protein Diisopropyl fluorophosphate Electrophoresis Polyacrylamide Gel Animal Science and Zoology Parasitology Peptide Hydrolases medicine.drug Cysteine |
| Zdroj: | Parasitology. 104:315-322 |
| ISSN: | 1469-8161 0031-1820 |
| Popis: | SUMMARYDetergent extracts ofTrypanosoma cruziepimastigotes catalysed the hydrolysis of a range of amino-acyl and peptidyl p-nitro-anilides and aminomethylcoumarins. At least three enzymes were detected that cleave Z–Phe–Arg–MCA. Two of these were optimally active at alkaline pH, the other at pH 4·0. Of the two enzymes with alkaline pH optima, one was a cysteine peptidase and was unable to cleave Bz–Arg–MCA readily, whilst the other cleaved Bz–Arg–MCA and was inhibited by diisopropyl fluorophosphate. The acidic enzyme was similar to cathespin L of other eukayrotes with respect to its pH profile, substrate-specificity and inhibitor-sensitivity. Evidence was presented that epimastigotes contain a cysteine-type dipeptidyl aminopeptidase, one or more aminopeptidases, and a serine peptidase that cleaves Boc–Ala–Ala–pNA. Digitonin solubilization of the activities from cells supports the hypothesis that the cathespin L-like enzyme and the dipeptidyl aminopeptidase are lysosomal, whilst the Bz–Arg–MCA hydrolase, the aminopeptidases and the Boc–Ala–Ala–pNA serine peptidase are cytosolic. |
| Databáze: | OpenAIRE |
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