Abstract
Precursor forms of lactase-phlorizin hydrolase, sucrase-isomaltase and aminopeptidase N were studied by pulse-labelling of organ-cultured human intestinal biopsies. After labelling the biopsies were fractionated by the Ca2+-precipitation method and the enzymes isolated by immunoprecipitation. The results indicate that the lactase-phlorizin hydrolase is synthesized as a Mr 245 000 polypeptide, which is intracellularly cleaved into its mature Mr 160 000 form. Sucrase-isomaltase is shown to be synthesized as a single chain precursor (Mr 245 000 and 265 000) while the precursor of aminopeptidase N is shown to be of apparently the same size as the mature enzyme (Mr 140 000 and 160 000).
| Original language | English |
|---|---|
| Journal | BBA General Subjects |
| Volume | 798 |
| Issue number | 2 |
| Pages (from-to) | 247-51 |
| Number of pages | 4 |
| ISSN | 0304-4165 |
| Publication status | Published - 1984 |