Nonidentity of chromogranin a and dopamine β-monooxygenase

Ruth A. Hogue-angeletti

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27 Scopus citations

Abstract

Dopamine β-monooxygenase (EC 1.14.17.1) and chromogranin A from bovine adrenal chromaffin granules were purified by established procedures and examined for evidence of structural identity. The minimum molecular weights were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and found to be 74,000 and 35,000, respectively. Amino acid analyses of the two proteins are distinct. Dopamine β-monooxygenase does not possess a free amino terminus, whereas chromogranin A has a leucine amino terminus. Analysis in the protein sequencer showed that chromogranin A contains only a single degradable polypeptide chain. Radioactive S-carboxymethyl derivatives of the two proteins were prepared to compare the soluble peptides after thermolysin digestion. These thermolytic peptides were isolated from columns of Dowex 50-X8 resin and both the peptide and radioactive traces revealed no evidence for similarity of the two proteins, either in toto or in part. Thus, although dopamine β-monooxygenase and chromogranin A may sometimes be copurified, they are distinct entities.

Original languageEnglish (US)
Pages (from-to)364-372
Number of pages9
JournalArchives of Biochemistry and Biophysics
Volume184
Issue number1
DOIs
Publication statusPublished - Nov 1977

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ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

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