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Distribution of reaction products in phospholipase A(2) hydrolysis

Wacklin, Hanna; Tiberg, Fredrik LU ; Fragneto, Giovanna and Thomas, Robert K. (2007) In Biochimica et Biophysica Acta - Biomembranes 1768(5). p.1036-1049
Abstract
We have monitored the composition of supported phospholipid bilayers during phospholipase A(2) hydrolysis using specular neutron reflection and ellipsometry. Porcine pancreatic PLA(2) shows along lag phase of several hours during which the enzyme binds to the bilayer surface, but only 5 +/- 3% of the lipids react before the onset of rapid hydrolysis. The amount of PLA(2), which resides in a 21 +/- 1 angstrom thick layer at the water-bilayer interface, as well as its depth of penetration into the membrane, increase during the lag phase, the length of which is also proportional to the enzyme concentration. Hydrolysis of a single-chain deuterium labelled d(31)-POPC reveals for the first time that there is a significant asymmetry in the... (More)
We have monitored the composition of supported phospholipid bilayers during phospholipase A(2) hydrolysis using specular neutron reflection and ellipsometry. Porcine pancreatic PLA(2) shows along lag phase of several hours during which the enzyme binds to the bilayer surface, but only 5 +/- 3% of the lipids react before the onset of rapid hydrolysis. The amount of PLA(2), which resides in a 21 +/- 1 angstrom thick layer at the water-bilayer interface, as well as its depth of penetration into the membrane, increase during the lag phase, the length of which is also proportional to the enzyme concentration. Hydrolysis of a single-chain deuterium labelled d(31)-POPC reveals for the first time that there is a significant asymmetry in the distribution of the reaction products between the membrane and the aqueous environment. The lyso-lipid leaves the membrane while the number of PLA(2) Molecules bound to the interface increases with increasing fatty acid content. These results constitute the first direct measurement of the membrane structure and composition, including the location and amount of the enzyme during hydrolysis. These are discussed in terms of a model of fatty-acid mediated activation of PLA(2). (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
keywords
phospholipase A(2), lag phase, fatty acid, lyso-lipid, supported bilayer, neutron reflection SILICA-WATER INTERFACE, LIPID-BILAYERS, FATTY-ACIDS, NEUTRON REFLECTIVITY, X-RAY, AIR/WATER INTERFACE, UNILAMELLAR VESICLES, STRUCTURAL-CHANGES, COMPONENT VOLUMES, DODECYL MALTOSIDE
in
Biochimica et Biophysica Acta - Biomembranes
volume
1768
issue
5
pages
1036 - 1049
publisher
Elsevier
external identifiers
  • scopus:34047259320
ISSN
0005-2736
DOI
10.1016/j.bbamem.2006.10.020
language
English
LU publication?
yes
id
158e17aa-ddc2-4f84-9eb2-9229439bf8a3 (old id 1026565)
date added to LUP
2008-02-06 18:34:42
date last changed
2017-07-30 04:25:51
@article{158e17aa-ddc2-4f84-9eb2-9229439bf8a3,
  abstract     = {We have monitored the composition of supported phospholipid bilayers during phospholipase A(2) hydrolysis using specular neutron reflection and ellipsometry. Porcine pancreatic PLA(2) shows along lag phase of several hours during which the enzyme binds to the bilayer surface, but only 5 +/- 3% of the lipids react before the onset of rapid hydrolysis. The amount of PLA(2), which resides in a 21 +/- 1 angstrom thick layer at the water-bilayer interface, as well as its depth of penetration into the membrane, increase during the lag phase, the length of which is also proportional to the enzyme concentration. Hydrolysis of a single-chain deuterium labelled d(31)-POPC reveals for the first time that there is a significant asymmetry in the distribution of the reaction products between the membrane and the aqueous environment. The lyso-lipid leaves the membrane while the number of PLA(2) Molecules bound to the interface increases with increasing fatty acid content. These results constitute the first direct measurement of the membrane structure and composition, including the location and amount of the enzyme during hydrolysis. These are discussed in terms of a model of fatty-acid mediated activation of PLA(2).},
  author       = {Wacklin, Hanna and Tiberg, Fredrik and Fragneto, Giovanna and Thomas, Robert K.},
  issn         = {0005-2736},
  keyword      = {phospholipase A(2),lag phase,fatty acid,lyso-lipid,supported
bilayer,neutron reflection
SILICA-WATER INTERFACE,LIPID-BILAYERS,FATTY-ACIDS,NEUTRON REFLECTIVITY,X-RAY,AIR/WATER INTERFACE,UNILAMELLAR VESICLES,STRUCTURAL-CHANGES,COMPONENT VOLUMES,DODECYL MALTOSIDE},
  language     = {eng},
  number       = {5},
  pages        = {1036--1049},
  publisher    = {Elsevier},
  series       = {Biochimica et Biophysica Acta - Biomembranes},
  title        = {Distribution of reaction products in phospholipase A(2) hydrolysis},
  url          = {http://dx.doi.org/10.1016/j.bbamem.2006.10.020},
  volume       = {1768},
  year         = {2007},
}