Adsorption of a phospholipid-hydroperoxide glutathione peroxidase into phospholipid monolayers at the air-water interface.
The interfacial behavior differences of two glutathione peroxidase isoforms have been investigated. The first isoform is the phospholipid-hydroperoxide glutathione peroxidase (EC 1.11.1.12) (GPx-4) isolated from rat testes and the second one is the cytosolic glutathione peroxidase (EC 1.11.1.9) (GPx-1) from bovine erythrocytes. Injected in the subphase buffer of a Langmuir trough, GPx-4 was able to adsorb quickly at the air-water interface whereas the GPx-1 was not. Then, the protein interaction with phospholipid monolayers was explored. Indeed, a monolayer of phospholipids containing a different number of polyunsaturated fatty acyl chains was prepared at the air-water interface. Under each kind of monolayer, the protein solution was injected and its adsorption was visualized by the measurement of successive pressure-area isotherms. We have, then, determined the molecular area increase due to the protein adsorption. It was found that the GPx-4 is adsorbed in each kind of monolayer tested whereas no molecular area increase was detected with the GPx-1. This indicates that the GPx-4 has a higher affinity for the interface, recovered or not by lipids, than the GPx-1. Moreover, the GPx-4 presents a different affinity for the phospholipid monolayers depending on the number of polyunsaturated fatty acyl chains.
Morandat
Sandrine
S
Laboratoire de Physico-Chimie Biologique, UMR-CNRS 5013, Bât. E. Chevreul 4ième étage, Université Claude Bernard Lyon I, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne Cedex, France. morandat@mpi-cbg.de
Bortolato
Muriel
M
Nicol
Fergus
F
Arthur
John R
JR
Chauvet
Jean-Paul
JP
Roux
Bernard
B
D000327:Adsorption; D000388:Air; D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005979:Glutathione Peroxidase / Q000737:chemistry* / Q000493:pharmacokinetics; D007527:Isoenzymes / Q000737:chemistry / Q000493:pharmacokinetics; D008563:Membrane Lipids / Q000737:chemistry*; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D010743:Phospholipids / Q000737:chemistry*; D051381:Rats; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry*
D007527:Isoenzymes; D008563:Membrane Lipids; D010743:Phospholipids; D014867:Water; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase