Synthesis, structural elucidation, and biochemical analysis of immunoactive glucuronosyl diacylglycerides of mycobacteria and corynebacteria.
J Org Chem
; 78(6): 2175-90, 2013 Mar 15.
Article
in En
| MEDLINE
| ID: mdl-23343519
ABSTRACT
Glucuronosyl diacylglycerides (GlcAGroAc2) are functionally important glycolipids and membrane anchors for cell wall lipoglycans in the Corynebacteria. Here we describe the complete synthesis of distinct acyl-isoforms of GlcAGroAc2 bearing both acylation patterns of (R)-tuberculostearic acid (C190) and palmitic acid (C160) and their mass spectral characterization. Collision-induced fragmentation mass spectrometry identified characteristic fragment ions that were used to develop "rules" allowing the assignment of the acylation pattern as C190 (sn-1), C160 (sn-2) in the natural product from Mycobacterium smegmatis, and the structural assignment of related C181 (sn-1), C160 (sn-2) GlcAGroAc2 glycolipids from M. smegmatis and Corynebacterium glutamicum. A synthetic hydrophobic octyl glucuronoside was used to characterize the GDP-mannose-dependent mannosyltransferase MgtA from C. glutamicum that extends GlcAGroAc2. This enzyme is an Mg(2+)/Mn(2+)-dependent metalloenzyme that undergoes dramatic activation upon reduction with dithiothreitol.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Stearic Acids
/
Bacterial Proteins
/
Glycolipids
/
Corynebacterium
/
Mycobacterium smegmatis
/
Glycerides
/
Magnesium
/
Mannosyltransferases
/
Mycobacterium
Type of study:
Prognostic_studies
Language:
En
Journal:
J Org Chem
Year:
2013
Document type:
Article
Affiliation country: