Early steps in glycosylphosphatidylinositol biosynthesis in Leishmania major

Terry K Smith, F C Milne, D K Sharma, A Crossman, J S Brimacombe, M A J Ferguson

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)

Abstract

A cell-free system based on washed Leishmania major membranes was labelled with GDP-[H-3]Man in the presence of synthetic glucosaminyl-phosphatidylinositol (GlcN-PI) and N-acetylglucosaminyl-phosphatidylinositol (GlcNAc-PI). In both cases, the major radiolabelled products were Man alpha 1-4GlcN alpha 1 -6myo-inositoll-HPO4-(sn-1,2-dipalmitoylglycerol) and Man alpha 1-4GlcN alpha 1-6myo-inositoll-HPO4- (sn-1-palmitoyl-2-lyso-glycerol), to which an additional D-mannose residue was added when a chase with an excess of GDP-Man was performed. The L. major cell-free system can therefore be used to observe the actions of four enzymes, namely GlcNAc-PI de-N-acetylase, Dol-P-Man-GlcN-PI alpha 1-4-mannosyltransferase, a phospholipase A(2)-like activity and a second alpha-mannosyltransferase activity. The substrate specificities of the first two of these enzymes were studied using a series of substrate analogues. GlcNAc-PI de-N-acetylase was tested against a variety of N-acylated GlcN-PI substrates and was able to cleave N-acetyl and N-propyl groups but not larger groups such as N-butyl, N-isobutyl, N-pentyl and N-hexyl. The Dol-P-Man-GlcN-PI alpha 1-4-mannosyltransferase activity required the amino group of the glucosamine residue and the D-configuration of the myo-inositol residue of the GlcN-PI acceptor substrate.

Original languageEnglish
Pages (from-to)393-400
Number of pages8
JournalBiochemical Journal
Volume326
Publication statusPublished - 1 Sept 1997

Keywords

  • PHOSPHATIDYLINOSITOL MEMBRANE ANCHOR
  • VARIANT SURFACE GLYCOPROTEIN
  • TRYPANOSOMA-BRUCEI
  • AFRICAN TRYPANOSOMES
  • GLYCOINOSITOL PHOSPHOLIPIDS
  • INOSITOL-ACYLATION
  • GLYCOSYLATED PHOSPHATIDYLINOSITOLS
  • GLUCOSAMINYL PHOSPHATIDYLINOSITOL
  • SACCHAROMYCES-CEREVISIAE
  • LIPOPHOSPHOGLYCAN

Fingerprint

Dive into the research topics of 'Early steps in glycosylphosphatidylinositol biosynthesis in Leishmania major'. Together they form a unique fingerprint.

Cite this