Identification of a variant surface glycoprotein (VSG) glycolipid precursor in Trypanosoma brucei

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7246753

Krakow, J; Hereld, D; Hart, G; Englund, P

The VSG coat protein of T. brucei has a glycolipid covalently attached to its C terminus which anchors it to the cell membrane. Compositional analyses of VSG, reported by several laboratories, indicate that the glycolipid contains myristic acid, glycerol, phosphate, inositol, several sugars, and ethanolamine. This glycolipid is found on the VSG polypeptide within 1 minute after translation, suggesting that prior to incorporation, it may exist in the cell as a preformed precursor. The authors have isolated a molecule which has properties consistent with being a VSG lipid precursor: it is highly polar and can be labelled by (/sup 3/H)myristate but not by (/sup 3/H)palmitate. It reaches steady-state during continuous labelling and shows rapid turnover in pulse-chase experiments, suggesting that it is a metabolic intermediate rather than an end product. When treated with HNO/sub 2/ it liberates phophatidylinositol, as does VSG, and, like VSG, releases dimyristylglycerol when treated with purified endogenous phospholipase C from trypanosomes. These data provide strong evidence that the glycolipid is a preformed precursor which is transferred to the VSG polypeptide en bloc.

• Research Organization: Johns Hopkins Medical School, Baltimore, MD
• OSTI ID: 7246753
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
CARBOHYDRATES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL COMPOSITION
COVALENCE
GLUCOPROTEINS
GLYCOLIPIDS
HEXADECANOIC ACID
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
MASTIGOPHORA
MEMBRANES
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PARASITES
PRECURSOR
PROTEINS
SACCHARIDES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TRYPANOSOMA