Differences in the Structure of A and B Forms of Human Monoamine Oxidase

Richard M. Cawthon, John E. Pintar, Florence P. Haseltine, Xandra O. Breakefield

Research output: Contribution to journalArticle

Abstract

Abstract: [3H]Pargyline‐labeled polypeptides associated with the A and B types of monoamine oxidase (MAO) activity in human tissues were analyzed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). [3H]Pargyline was bound to MAO A in a crude mitochondrial fraction from the placental trophoblast of a male newborn and to MAO B in blood platelets from the umbilical vein of the same newborn. [3H]Pargyline was also bound to MAO A and B in a crude mitochondrial fraction from cultured skin fibroblasts of a male adult and to MAO B in blood platelets from the same individual. Specific labeling of proteins associated with type A or type B activity in fibroblast cells was achieved by preincubation with selective B or A inhibitors, respectively. For all tissues, SDS‐PAGE of [3H]pargyline‐bound samples revealed a labeled protein band of apparent molecular weight 63,000 for MAO A and 60,000 for MAO B. When SDS‐solubilized, [3H]pargyline‐labeled MAO A and B proteins from the same male newborn were subjected to limited proteolysis and one‐dimensional peptide mapping in SDS gels, different patterns of [3H]pargyline‐labeled peptides were obtained. These findings indicate that distinct enzyme molecules are associated with the A and B types of human MAO activity.

Original languageEnglish (US)
Pages (from-to)363-372
Number of pages10
JournalJournal of Neurochemistry
Volume37
Issue number2
DOIs
StatePublished - Aug 1981

Keywords

  • Isoenzymes
  • Monoamine oxidase
  • Pargyline
  • Peptide mapping
  • Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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  • Cite this

    Cawthon, R. M., Pintar, J. E., Haseltine, F. P., & Breakefield, X. O. (1981). Differences in the Structure of A and B Forms of Human Monoamine Oxidase. Journal of Neurochemistry, 37(2), 363-372. https://doi.org/10.1111/j.1471-4159.1981.tb00464.x