Immunological identification of human platelet mitochondrial DNA topoisomerase I.

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Kosovsky MJ, Soslau G

Immunological identification of human platelet mitochondrial DNA topoisomerase I.

Biochim Biophys Acta. 1993 Jun 24;1164(1):101-7.

PubMed ID

8390858 [ View in PubMed

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Abstract

A nuclear human blood platelets have been used to study mitochondrial topoisomerase activity in the absence of nuclear contamination. Previous work utilizing this novel system demonstrated that platelet mitochondria contain type-I topoisomerase (Kosovsky, M.J. and Soslau, G. (1991) Biochim. Biophys. Acta 1078, 56-62). The present work has demonstrated that mitochondrial topoisomerase activity was inhibited by the specific topoisomerase-I inhibitor, topotecan, yet was not affected by a specific topoisomerase-II inhibitor, VM-26. These results confirm that platelet mitochondria contain topoisomerase I, yet do not contain a detectable level of topoisomerase-II activity. It has been demonstrated for the first time that antibodies directed against nuclear topo I cross-react with mitochondria topo I. Furthermore, immunoblot analysis of platelet mitochondrial proteins, in conjunction with renaturation studies, has led to the identification of a catalytically active 60-kDa form of mitochondrial topoisomerase I.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Topotecan	DNA topoisomerase I, mitochondrial	Protein	Humans	Unknown	Inhibitor	Details