title: The effects of protein hydrophobic exposure on the slope of the line in the deltapi vs pi(i) plot.
abstract: The deltapi vs pi(i) curve from monolayer surface pressure detection is a powerful method to characterize the membrane insertion. The deltapi vs pi(i) curve is fixed by two parameters, the pi(c) and the slope. The intersected point (pi(c)) of deltapi vs pi(i) curve with abscissa is generally used as a quantitative measure of the membrane insertion ability of a protein. In the current work we demonstrate a correlation between the variation in the slope of the deltapi vs pi(i) curve with protein hydrophobic exposure by performing monolayer experiments on three different proteins, human apolipoprotein H, trichosanthin, and mutant trichosanthin. The value of /slope/ increases gradually following the degree of hydrophobic exposure. These findings suggest that the two parameters, the pi(c) and the slope, will complement each other to interpret the lipid/protein interaction involved in membrane insertion.
authors.affiliation: Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, People's Republic of China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.forename: Ying-Jie
authors.initials: YJ
authors.lastname: Lu
authors.forename: Shao-Xiong
authors.initials: SX
authors.lastname: Wang
authors.forename: Sen-Fang
authors.initials: SF
authors.lastname: Sui
mesh_terms: D002462:Cell Membrane / Q000187:drug effects; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D009154:Mutation; D010715:Phosphatidylglycerols / Q000737:chemistry / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism; D011312:Pressure; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013499:Surface Properties; D015978:Trichosanthin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053482:beta 2-Glycoprotein I
chemical_list: D006023:Glycoproteins; D008563:Membrane Lipids; D010715:Phosphatidylglycerols; D010743:Phospholipids; D053482:beta 2-Glycoprotein I; D015978:Trichosanthin; C030345:1,2-dipalmitoylphosphatidylglycerol