ζ-Crystallin catalyzes the reductive activation of 2,4,6-trinitrotoluene to generate reactive oxygen species: a proposed mechanism for the induction of cataracts
Exposure to 2,4,6-trinitrotoluene (TNT) has been shown to cause induction of cataract in which oxidative stress plays a critical role. From bovine lens we purified to homogeneity and identified an enzyme that catalyzes the reduction of TNT, resulting in the production of reactive oxygen species. The...
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Published in | FEBS letters Vol. 478; no. 3; pp. 295 - 298 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Elsevier B.V
04.08.2000
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Subjects | |
Online Access | Get full text |
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Summary: | Exposure to 2,4,6-trinitrotoluene (TNT) has been shown to cause induction of cataract in which oxidative stress plays a critical role. From bovine lens we purified to homogeneity and identified an enzyme that catalyzes the reduction of TNT, resulting in the production of reactive oxygen species. The final preparation of TNT reductase showed a single band with a subunit molecular weight of 38 kDa on SDS–PAGE. Sequence data from peptides obtained by digestion with lysylendopeptidase
Achromobacter protease I (API) revealed that TNT reductase is identical to ζ-crystallin. Superoxide anions were formed during reduction of TNT by ζ-crystallin, though negligible enzyme activity or protein content for superoxide dismutase, a superoxide scavenging enzyme, was found in the lens. Thus, the present results suggest that the induction of cataracts by TNT may be associated with increased oxidative stress, as a result of reductive activation of TNT generating superoxide anions, there being minimal antioxidant enzyme activity for defense against reactive oxygen species exogenously produced in the lens. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0014-5793 1873-3468 |
DOI: | 10.1016/S0014-5793(00)01841-X |