DARPP-32, a dopamine- and adenosine 3':5'-monophosphate-regulated phosphoprotein enriched in dopamine-innervated brain regions. II. Purification and characterization of the phosphoprotein from bovine caudate nucleus

J Neurosci. 1984 Jan;4(1):99-110. doi: 10.1523/JNEUROSCI.04-01-00099.1984.


DARPP-32 is a neuronal phosphoprotein of Mr = 32,000, originally identified in rat brain (Walaas, S.I., D.W. Aswad, and P. Greengard (1983) Nature 301: 69-72). This protein has now been identified in bovine caudate nucleus cytosol and purified 435-fold to apparent homogeneity as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purification procedure involved acid extraction at pH 2, CM-cellulose chromatography, DEAE-cellulose chromatography, hydroxylapatite chromatography, and gel filtration on Ultrogel AcA 44. The purified catalytic subunit of cAMP-dependent protein kinase catalyzed the incorporation of 0.96 mol of phosphate/mol of purified DARPP-32. Phosphorylation occurred exclusively on threonine. The isoelectric point of dephospho-DARPP-32 was 4.7, and that of phospho-DARPP-32 was 4.6. The amino acid composition showed a high content of glutamate/glutamine and proline, and a low content of hydrophobic amino acids. DARPP-32 was found to have a Stokes radius of 34 A and a sedimentation coefficient of 2.05 S, indicating that it exists as an elongated monomer.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acids / analysis
  • Animals
  • Cattle
  • Caudate Nucleus / drug effects
  • Caudate Nucleus / metabolism*
  • Cyclic AMP / physiology*
  • Dopamine / physiology*
  • Dopamine and cAMP-Regulated Phosphoprotein 32
  • Electrophoresis, Polyacrylamide Gel
  • Isoelectric Focusing
  • Molecular Weight
  • Nerve Tissue Proteins / isolation & purification*
  • Nerve Tissue Proteins / metabolism
  • Phosphoproteins / isolation & purification*
  • Phosphoproteins / metabolism
  • Phosphorylation
  • Protein Conformation


  • Amino Acids
  • Dopamine and cAMP-Regulated Phosphoprotein 32
  • Nerve Tissue Proteins
  • Phosphoproteins
  • Cyclic AMP
  • Dopamine