The biosynthesis and maturation of the human intestinal lactase-phlorizin hydrolase (LPH; EC 3.2.1.23-3.2.1.62) has been studied in cultured intestinal biopsies and mucosal explants. Short time pulse labelling revealed on high mannose intermediate of Mr 215,000 which was converted upon endo-beta-N-acetylglucosaminidase H (endo-H) digestion to a polypeptide of Mr 200,000. The brush border form of LPH was revealed after longer pulse periods and has Mr 160,000. It possesses mainly complex oligosaccharide chains and, owing to its partial endo-H sensitivity, at least one chain of the high mannose type. Leupeptin partially inhibited the appearance of the Mr-160,000 polypeptide. Monensin treatment of biopsies resulted in the modification of the Mr-160,000 species to the Mr-140,000 molecule, which was endo-H sensitive. Pulse-chase analysis indicated a slow post-translational processing of the high mannose precursor (Mr 215,000) to yield the mature brush-border form (Mr 160,000) of LPH. Our results further indicate that LPH is synthesized as a single polypeptide precursor which is intracellularly cleaved to yield the mature brush border of LPH. The data presented suggest that this cleavage occurs during the translocation of the molecule across the Golgi complex.
Skip Nav Destination
Follow us on Twitter @Biochem_Journal
Article navigation
January 1987
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkAdvertising
Research Article|
January 15 1987
Biosynthesis and maturation of lactase-phlorizin hydrolase in the human small intestinal epithelial cells
Publisher: Portland Press Ltd
Online ISSN: 1470-8728
Print ISSN: 0264-6021
© 1987 London: The Biochemical Society
1987
Biochem J (1987) 241 (2): 427–434.
Citation
H Y Naim, E E Sterchi, M J Lentze; Biosynthesis and maturation of lactase-phlorizin hydrolase in the human small intestinal epithelial cells. Biochem J 15 January 1987; 241 (2): 427–434. doi: https://doi.org/10.1042/bj2410427
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Biochemical Society Member Sign in
Sign InSign in via your Institution
Sign in via your InstitutionGet Access To This Article
Follow us on Twitter @Biochem_Journal
Open Access for all
We offer compliant routes for all authors from 2025. With library support, there will be no author nor reader charges in 5 journals. Check here |
![]() View past webinars > |