Conversion of a high molecular weight latent beta-TGF from chicken embryo fibroblasts into a low molecular weight active beta-TGF under acidic conditions

Biochem Biophys Res Commun. 1985 Dec 31;133(3):1026-34. doi: 10.1016/0006-291x(85)91239-2.

Abstract

A latent beta-TGF activity is spontaneously released into serum-free culture medium by chicken embryo fibroblasts. Anchorage-independent growth activity measured on NRK-49F indicator cells, of this latent beta-TGF can be revealed by four different treatments: acidification, alkalinisation, exposure to urea, and heating to 100 degrees C for 3 minutes. This lact activating treatment indicates that latent beta-TGF activation in vitro is non-enzymatic. Active beta-TGF exists in a low molecular weight form 16 Kd (apparent) in 1M acetic acid, which elutes on reverse phase (FPLC) between 33-35% acetonitrile. Under neutral conditions only a high molecular weight form excluded on Biogel P60 is observed. This form is poorly active on NRK-49F for anchorage independent growth but can be fully activated by prior acidification. Rechromatography of the latent beta-TGF-containing fractions under acidic conditions converts the high molecular weight form to an apparent 16 Kd active form. We suggest that the high molecular weight form may correspond to a complex of a beta-TGF associated with a carrier or binding protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biotransformation
  • Chick Embryo
  • Clone Cells
  • Culture Media
  • Fibroblasts / metabolism
  • Hydrogen-Ion Concentration
  • Kidney / metabolism
  • Molecular Weight
  • Peptides / metabolism*
  • Rats
  • Transforming Growth Factors

Substances

  • Culture Media
  • Peptides
  • Transforming Growth Factors