p-NN'-phenylenebismaleimide, a specific cross-linking agent for F-actin

Biochem J. 1978 Dec 1;175(3):1023-32. doi: 10.1042/bj1751023.


Covalent cross-links can be inserted between the subunits of F-actin by using p-NN'-phenylenebismaleimide. Cross-linking reaches its maximum value when one molecule of reagent has reacted with each actin subunit. p-NN'-Phenylenebismaleimide reacts initially with a cysteine residue on one subunit, the slower cross-linking reaction involving a lysine residue on a neighbouring subunit. Hydrolysis of the actin-bound reagent limits the extent of cross-linking. Quantitative analysis of the amounts of cross-linked oligomers seen on polyacrylamide gels containing sodium dodecyl sulphate suggests that neither the binding of the reagent to actin nor the formation of cross-links introduces strain into the structure. The cross-links do not join together different F-actin filaments, and evidence is presented that suggests that the cross-links join subunits of the same long-pitched helix.

MeSH terms

  • Actins*
  • Chemical Phenomena
  • Chemistry
  • Cysteine
  • Electrophoresis, Polyacrylamide Gel
  • Kinetics
  • Maleimides*
  • Temperature


  • Actins
  • Maleimides
  • Cysteine