Document Detail


Hydrolysis of 2-acyl-sn-glycero-3-phosphocholines in guinea pig heart mitochondria.
MedLine Citation:
PMID:  2257116     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Although both 2-acyl-sn-glycero-3-phosphocholine and 1-acyl-sn-glycero-3-phosphocholine may be produced from phosphatidylcholine hydrolysis, studies on the former have lagged behind that of the latter. In this study a lysophospholipase A2 that hydrolyses 2-acyl-sn-glycero-3-phosphocholine has been characterized in guinea pig heart mitochondria. The lysophospholipase A2 activity was not dependent on Ca2+ and was inhibited differentially by saturated and unsaturated fatty acids. This lysophospholipase A2 activity was able to discriminate among different molecular species of 2-acyl-sn-glycero-3-phosphocholines when they were presented individually or in pairs. The order of decreasing rates of hydrolysis of different molecular species of 2-lysophosphatidylcholines, when the substrates were presented singly, was 18:2 greater than 20:4 greater than 18:1 greater than 16:0. A differential inhibition of the rate of hydrolysis of the individual substrates was observed when the substrates were presented in pairs. The degree of inhibition was dependent on the molar ratio of the mixed substrates. The characteristics of the enzyme suggest that involvement in the selective release of fatty acids from mitochondrial phosphatidylcholine would depend on a high selectivity of phospholipase A1 for different molecular species of phosphatidylcholine. A lysophospholipase A1 activity was also characterized in the mitochondria with a distinct acyl specificity from the lysophospholipase A2. Other characteristics of the two lysophospholipases suggest that the two reactions are not catalysed by the same enzyme.
Authors:
K Badiani; L Page; G Arthur
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Biochemistry and cell biology = Biochimie et biologie cellulaire     Volume:  68     ISSN:  0829-8211     ISO Abbreviation:  Biochem. Cell Biol.     Publication Date:  1990 Sep 
Date Detail:
Created Date:  1991-01-31     Completed Date:  1991-01-31     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8606068     Medline TA:  Biochem Cell Biol     Country:  CANADA    
Other Details:
Languages:  eng     Pagination:  1090-5     Citation Subset:  IM    
Affiliation:
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Canada.
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MeSH Terms
Descriptor/Qualifier:
Animals
Guinea Pigs
Lysophosphatidylcholines / metabolism*
Lysophospholipase / metabolism*
Mitochondria, Heart / enzymology*
Substrate Specificity
Chemical
Reg. No./Substance:
0/Lysophosphatidylcholines; EC 3.1.1.5/Lysophospholipase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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