Purification and Characterization of Maturation-Promoting Factor in Fish

Dev Biol. 1992 Jan;149(1):8-15. doi: 10.1016/0012-1606(92)90259-j.


Maturation-promoting factor (MPF) activity has been demonstrated for the first time in fish oocytes. We purified MPF from a 100,000g supernatant of crushed, naturally spawned carp oocytes using four chromatography columns: Q-Sepharose Fast-Flow, p13suc1-affinity Sepharose, Mono S, and Superose 12. The final preparation was purified over 1000-fold with a recovery of about 1%. On Superose 12, MPF eluted as a single peak with an apparent molecular weight of 100 kDa. SDS-PAGE analysis of the active fractions after Superose 12 revealed the presence of four proteins of 33, 34, 46, and 48 kDa. A monoclonal antibody against the PSTAIR sequence of cdc2 kinase recognized the 33- and 34-kDa proteins for which the 46- and 48-kDa proteins are endogenous substrates. The 46- and 48-kDa proteins were recognized by a monoclonal antibody against Escherichia coli-produced goldfish cyclin B, but not by an anti-cyclin A antibody. When oocytes were matured in the presence of 32P, the labeling was seen with the 34-kDa protein, but not with the 33-kDa protein. The 34-kDa protein corresponded to the MPF activity, but the 33-kDa protein did not. These findings indicate that carp MPF is a complex of cdc2 kinase and cyclin B, and further that active MPF contains the phosphorylated form of cdc2 kinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CDC2 Protein Kinase / chemistry
  • Carps / embryology*
  • Female
  • Goldfish / embryology*
  • Maturation-Promoting Factor / chemistry
  • Maturation-Promoting Factor / isolation & purification*
  • Oocytes / chemistry
  • Oocytes / enzymology*
  • Oocytes / growth & development
  • Phosphorylation
  • Xenopus laevis


  • CDC2 Protein Kinase
  • Maturation-Promoting Factor