|
| PROTEOLYTIC ACTIVITY IN EXTRACTS OF ENTAMOEBA-INVADENS AND ENTAMOEBA-HISTOLYTICA - A COMPARATIVE-STUDY |
|
|
Ruy Pérez Montfort; ENGELMAYER, J; OstoaSaloma, P; GutierrezKobeh, L; Cabrera, N; Becker, I; |
|
 |
Publication date:
1994 |
| Journal:
ACTA PROTOZOOL |
| Volume:
33 |
| Issue:
4 |
| Pages:
213-218 |
|
|
| Two species of amoebae: Entamoeba invadens and Entamoeba histolytica are potentially invasive in reptiles and certain primates, respectively. Since proteinases may be involved in pathogenic mechanisms (tissue necrosis), at least in E. histolytica, it was of interest to compare their proteases. We compared the sensitivity of proteolytic activity in extracts of both species of amoebae to pH, temperature, and proteinase inhibitors of different catalytic classes. Proteinases in extracts of E. invadens were mainly inhibited in the presence of chelating agents, in contrast to the partial or complete activation for proteinases of E. histolytica. The pH-dependence curves for both types of extracts were also different. When hide powder azure was used as a substrate, extracts of E. histolytica showed a maximum of activity at pH 7 and a shoulder at pH 5, while extracts of E. invadens only showed a maximum at pH 7.4. With azocasein as substrate, extracts of E. invadens had two maxima of activity at pH 6 and 7.4, while extracts of E. histolytica had a maximum at pH 6 and a shoulder at pH 7.4. The temperature optimum for the digestion of azocasein was 60 degrees C for extracts of E. invadens and E. histolytica, but proteolytic activity in the latter was more resistant to temperature.Analysis of lysates from both species of amoebae by substrate-gel electrophoresis, also showed marked differences in the observed lysis zones. E. histolytica showed six hydrolysis zones at with relative molecular masses of 66, 58, 42, 31, 28, and 23 kDa; and E. invadens showed only two zones, with relative molecular masses of 52 and 45 kDa. We conclude that although both species of amoebae contain mainly cysteine proteinases, the enzymes contained in both types of cells are different. |
|
| Keywords:
ENTAMOEBA INVADENS ENTAMOEBA-HISTOLYTICA proteolytic activity INHIBITOR SUBSTRATE GEL ELECTROPHORESIS |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
 |
| - |
|
| - |
|
|
