Purification of cysteine proteinases from trichomonads using bacitracin-sepharose |
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Authors: | Joseph W. Irvine Graham H. Coombs Michael J. North |
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Affiliation: | Laboratory for Biochemical Parasitology, Department of Zoology, University of Glasgow, Glasgow, UK; Department of Biological and Molecular Science, University of Stirling, Stirling, UK |
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Abstract: | Abstract Bacitracin affinity chromatography has been used to purify proteinases of the parasitic protozoon Tritrichomonas foetus . It proved superior to other affinity chromatography methods we have tested for the purification of trichomonad proteinases and should prove a useful procedure for purifying cysteine proteines from these parasites and other parasitic protozoa. The main cysteine proteinases of T. foetus were purified over 100-fold to be free from the majority of other cell proteins. About 90 μg of protein containing 1.56-fold more proteinase activity than was detectable in the original cell lysate was obtained from 109 cells (7.2 mg protein). SDS-PAGE revealed that the eluate contained two main Coomassie blue-staining bands. N-terminal amino acid sequence analysis of these proteins confirmed that one of them was a cysteine proteinase with unusuall features. Cysteine proteinases were also purified from cell lysates of Trichomonas vaginalis and a N-terminal sequence determined. This is the first amino acid sequence information that has been obtained for trichomonad cysteine proteinases. The method was also used to purify proteinases from the medium of T. foetus cultures. Some selectivity in binding of the proteinases to the affinity column was found. |
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Keywords: | Cysteine proteinases Tritrichomonas foetus Parasitic protozoa |
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