Glycolipid A, the precursor of the glycosyl-phosphatidylinositol (GPI) anchor of the trypanosome variant surface glycoprotein, is constructed in two phases. First, the glycan is assembled on phosphatidylinositol (PI), yielding a glycolipid termed A'. Second, glycolipid A' undergoes fatty acid remodelling, by deacylation and reacylation, to become the dimyristoyl species glycolipid A. In this paper, we examine the fatty acid content of glycolipid A' and its cellular progenitors. A' contains exclusively stearate at the sn-1 position and a complex mixture of fatty acids (including 18:0, 18:1, 18:2, 20:4 and 22:6) at sn-2. Presumably these fatty acids derive from stearate-containing PI species which initially enter the biosynthetic pathway. We compared the diacylglycerol species from glycolipid A' with those from phosphatidylinositol to determine whether a subset of stearate-containing PIs is utilized for GPI biosynthesis. We found that the spectrum of stearate-containing diacylglycerols in PI is similar to that in A', although the proportions of each compound differ. Total PI in general was highly enriched in stearate-containing species. Differences in composition between glycosylated PI and total cellular PI may be due to the substrate specificity of the sugar transferase which initiates the GPI biosynthetic pathway. Alternatively, the species of PI present at the endoplasmic reticulum site of GPI biosynthesis may differ from those in total PI.
Skip Nav Destination
Follow us on Twitter @Biochem_Journal
Article navigation
May 1994
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkAdvertising
Research Article|
May 01 1994
The fatty acids in unremodelled trypanosome glycosyl-phosphatidylinositols
T L Doering;
T L Doering
*Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, U.S.A.
Search for other works by this author on:
M S Pessin;
M S Pessin
†Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, U.S.A.
Search for other works by this author on:
G W Hart;
G W Hart
*Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, U.S.A.
Search for other works by this author on:
D M Raben;
D M Raben
*Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, U.S.A.
Search for other works by this author on:
P T Englund
P T Englund
*Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, U.S.A.
Search for other works by this author on:
Publisher: Portland Press Ltd
Online ISSN: 1470-8728
Print ISSN: 0264-6021
© 1994 The Biochemical Society, London
1994
Biochem J (1994) 299 (3): 741–746.
Citation
T L Doering, M S Pessin, G W Hart, D M Raben, P T Englund; The fatty acids in unremodelled trypanosome glycosyl-phosphatidylinositols. Biochem J 1 May 1994; 299 (3): 741–746. doi: https://doi.org/10.1042/bj2990741
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 > |