Interaction of the interdigitated DPPG or DPPG/DMPC bilayer with human erythrocyte band 3: differential scanning calorimetry and fluorescence studies.
Human erythrocyte band 3 reconstituted into phospholipid vesicles has been used for studying the interaction of interdigitated lipid bilayer with an integral membrane protein. The interdigitated gel phase in DPPG/band 3 or DPPG/DMPC/band 3 systems was induced with polymyxin B (PMB) or Tris+. The phase transitions of the vesicles were detected with high-sensitivity differential scanning calorimetry (DSC). The results indicated that band 3 does not cause significant alterations in the interdigitated phase of phospholipids, with only a little decrease of the phase transition enthalpies. Fluorescence measurements showed that the transition of phospholipid/band 3 systems from the non-interdigitated to interdigitated phase is accompanied by marked intrinsic fluorescence changes of band 3. The interdigitated phase of DPPG or DPPG/DMPC vesicles increases the intrinsic fluorescence intensity of band 3 and significantly decreases the accessibility of certain tryptophan residues on the protein to Cs+.
Wang
P Y
PY
Institute of Biophysics, Academia Sinica, Beijing, China.
Lu
J Z
JZ
Chen
J W
JW
Hwang
F
F
D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D005453:Fluorescence; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry; D011487:Protein Conformation
D001457:Anion Exchange Protein 1, Erythrocyte; D008051:Lipid Bilayers; D010715:Phosphatidylglycerols; D010743:Phospholipids; D004134:Dimyristoylphosphatidylcholine; C030345:1,2-dipalmitoylphosphatidylglycerol