ISSN:
0263-6484
Keywords:
Phospholipase A2
;
Trypanosoma congolense
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Phospholipase A2 was isolated from Trypanosoma congolense and purified to electrophoretic homogeneity. The enzyme appeared to exist in a dimeric form with subunit molecular weights of 16 500 and 18 000. It had a pH optimum of 6·8. Kinetic analysis with different substrates, showed that the enzyme had exceptional specificity for 1,2,dimyristoyl-sn-phosphatidylcholine and 1,2,dioleoyl-sn-phosphatidylcholine with Km values of 1·85 × 10-3 M and 2·12 × 10-3 M respectively. The Arrhenius plot was linear with an activation energy of 5·8 kcal mol-1. Inhibition studies with parahydroxymercuribenzoate and tri-butyltinoxide were positive thus implicating a thiol group at the catalytic site of the enzyme. The enzyme was stable to heat treatment and possessed haemolytic and anticoagulating properties.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cbf.290110208
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