ABSTRACT
The effects of a new intestinal peptide, inhibiting enterocytogenin (IEG) derived from pig intestinal mucosa were studied in vitro on 3T3 mouse fibroblasts and L5178Y mouse lymphoma cell line. IEG caused considerable growth inhibition together with specific morphological changes, necrotic effects as well as formation of monolayers at the highest concentration applied (1000 micrograms/ml). A biologically active fraction (IEG-BAF) derived by further purification of IEG by gel-filtration, proved to possess most of the described activity. The concentrations of IEG and IEG-BAF inhibiting the growth of L5178Y lymphoma cells by 50% (IC50 values) were calculated to be 759 micrograms/ml and 192 micrograms/ml, respectively. IEG-BAF has a molecular mass of 4450 +/- 180 Da and is most probably a peptidylnucleotidate as revealed by spectral analysis.