Purification and properties of a 90-kDa nuclear actin-binding protein

Proc Soc Exp Biol Med. 1986 Apr;181(4):479-85. doi: 10.3181/00379727-181-42280.

Abstract

A 90 kDa actin-binding nuclear protein (ABNP) with a pI of 5.2 has been purified from the 0.7 M NaCl extracted residue fraction of chromatin prepared from Novikoff hepatoma cell nuclei. This residue fraction was previously shown to contain nuclear actin. Although twice the size, similar in pI, and similar in amino acid composition to actin, the tryptic peptide map for ABNP is distinct and contains the appropriate number of tyrosine-containing tryptic peptides for a protein of 90,000 molecular weight. A comparison of the amino acid composition of ABNP with those reported in the literature for gelsolin and villin, using a calculation of S delta Q as an indication of relatedness, results in values of 30 and 27, respectively. Actin-binding activity, however, was demonstrated for both crude and gel purified ABNP using a gel-overlay technique that employs 125I-G-actin to detect specific actin-binding proteins.

Publication types

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

MeSH terms

  • Amino Acids / analysis
  • Animals
  • Carrier Proteins / isolation & purification*
  • Cell Line
  • Cell Nucleus / analysis
  • Chromatin / analysis
  • Electrophoresis, Polyacrylamide Gel
  • Gelsolin
  • Isoelectric Point
  • Liver Neoplasms, Experimental / ultrastructure
  • Microfilament Proteins*
  • Molecular Weight
  • Peptide Fragments / analysis
  • Rats
  • Trypsin / metabolism

Substances

  • Amino Acids
  • Carrier Proteins
  • Chromatin
  • Gelsolin
  • Microfilament Proteins
  • Peptide Fragments
  • brevin
  • Trypsin