Human erythrocyte band 7.2b is preferentially labeled by a photoreactive phospholipid.
A head-group modified, photoreactive analog of phosphatidylethanolamine, N-([125I]iodo-4-azidosalicy- lamidyl)-1,2-dilauryl-sn-glycero-3-phosphatidylethanolamine ([125I]-N-ASA-DLPE), has been used in photoaffinity labeling studies of proteins of the human erythrocyte membrane. [125I]-N-ASA-DLPE was shown to be preferentially incorporated into a protein with an apparent molecular weight of 31 kDa. Protein sequencing and immunoprecipitation were used to identify this protein as the erythrocyte membrane protein, band 7.2b or stomatin. A sulphydryl-reactive ligand, 4-hydroxy-3-(iodo-[125I])-N-[2-(2-pyridinyldithio)ethyl]- benzenepropanamide ([125I]-PDA), was also shown to preferentially label band 7.2b. We propose that band 7.2b may act as a site of transbilayer reorientation of membrane phospholipids.
Desneves
J
J
School of Chemistry, La Trobe University, Bundoora, Victoria, Australia.
Berman
A
A
Dynon
K
K
La Greca
N
N
Foley
M
M
Tilley
L
L
D000345:Affinity Labels / Q000138:chemical synthesis / Q000378:metabolism; D001386:Azides / Q000138:chemical synthesis / Q000378:metabolism*; D001798:Blood Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000378:metabolism*; D006801:Humans; D007457:Iodine Radioisotopes; D008565:Membrane Proteins; D008961:Models, Structural; D010666:Phenylpropionates / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000138:chemical synthesis / Q000378:metabolism*; D017433:Protein Structure, Secondary; D011725:Pyridines / Q000378:metabolism
C100614:4-hydroxy-3-iodo-N-(2-(2-pyridinyldithio)ethyl)benzenepropanamide; D000345:Affinity Labels; D001386:Azides; D001798:Blood Proteins; D007457:Iodine Radioisotopes; D008565:Membrane Proteins; C100613:N-(iodo-4-azidosalicylamidyl)-1,2-dilauryl-sn-glycero-3-phosphatidylethanolamine; D010666:Phenylpropionates; D010714:Phosphatidylethanolamines; D011725:Pyridines; C036860:STOM protein, human