Use of monoclonal antibody for comparative studies of monoamine oxidase B in mitochondrial extracts of human brain and peripheral tissues

R. M. Denney, R. R. Fritz, N. T. Patel, Steven Widen, C. W. Abell

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

Monoamine oxidase B (MAO B; EC 1.4.3.4) activity in detergent extracts of mitochondria for autopsy brain (gray matter and medulla) liver, lung, and kidney from a single individual and from pooled, human platelets could be immunoprecipitated by a monoclonal anti-human platelet MAO B antibody (MAO-1C2) in combination with appropriate secondary reagents. MAO A activity, which was detected in brain, liver, lung, and kidney, was not immunoprecipitated under the same conditions. All MAO B-containing extracts, regardless of tissue source, inhibited immunoprecipitation of [3H]pargyline-labeled human platelet MAO, and the shapes of the inhibition curves were identical. The concentration of immunologically detectable MAO B protein in the extracts was estimated from immunoprecipitation competition data by reference to a standard curve relating observed inhibition of immunoprecipitation to the concentration of catalytically active platelet MAO added (estimated from [3H]pargyline binding data). MAO B protein concentrations measured by this radioimmunoassay were similar to concentrations of active MAO B as measured by pargyline binding. These results demonstrate that in the brain and peripheral tissues studied, molecules with MAO B activity share a unique antigenic determinant and similar catalytic efficiency. They also extend previous observations that MAO B molecules extracted from mitochondria bear an antigenic determinant which is not present on MAO A molecules. These results demonstrate the validity of new competitive radioimmunoassay for active plus inactive MAO B concentration in human platelet extracts and extracts of mitochondria from tissues. This radioimmunoassay should complement [3H]pargyline binding assays and enzyme assays in studies designed to clarify the mechanisms of genetic, disease, and treatment factors which lead to differences in MAO B function among individuals.

Original languageEnglish (US)
Pages (from-to)60-68
Number of pages9
JournalMolecular Pharmacology
Volume24
Issue number1
StatePublished - Sep 8 1983
Externally publishedYes

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ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmacology

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