Action of trypanosomal lipolytic enzymes on the membrane-form variant surface glycoprotein of trypanosoma brucei
The membrane-form variant surface glycoprotein (mfVSG) of Trypanosoma brucei is anchored in the plasma membrane by myristoyl residues ester-linked to glycerophosphoethanolamine. The authors have extracted (myristoyl-/sup 3/H)-mfVSG from trypanosomes incubated with (/sup 3/H)-myristate and have isolated the protein by reverse phase HPLC. The extraction solvent, 20% acetonitrile in 0.1% trifluoroacetic acid, prevents lipolysis of the mfVSG during isolation. The mfVSG was shown to be homogeneous by SDS-PAGE, with an apparent molecular mass ratio of 66,000. No other proteins were labelled with (/sup 3/H)-myristate. The major lipolytic enzyme of T. brucei, phospholipase A/sub 1/, did not release myristate from mfVSG to any significant extent, though the enzyme readily hydrolyzes ester linkages of myristoyl phospholipids and p-nitrophenylmyristate. Trypanosomal membranes contain a phosphodiesterase which releases (/sup 3/H)-1,2-diglyceride from (/sup 3/H)-myristoyl-mfVSG. The phospholipase A/sub 1/ can be separated from the myristoyl-releasing activity (phosphodiesterase) by centrifugation, affinity chromatography and anion-exchange chromatography.
- Research Organization:
- Guelph-Waterloo Centre for Graduate Work in Chemistry, Ontario
- OSTI ID:
- 6986117
- Report Number(s):
- CONF-8606151-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:6; ISSN FEPRA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
CARBOHYDRATES
CARBOXYLESTERASES
CELL CONSTITUENTS
CELL MEMBRANES
CHROMATOGRAPHY
ELECTROPHORESIS
ENZYME ACTIVITY
ENZYMES
ESTERASES
GLUCOPROTEINS
HYDROLASES
ION EXCHANGE CHROMATOGRAPHY
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LABELLING
LIPASE
LIQUID COLUMN CHROMATOGRAPHY
MASTIGOPHORA
MEMBRANES
ORGANIC COMPOUNDS
PARASITES
PHOSPHODIESTERASES
PROTEINS
REACTION KINETICS
SACCHARIDES
SEPARATION PROCESSES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TRYPANOSOMA