The effects of protein hydrophobic exposure on the slope of the line in the deltapi vs pi(i) plot.
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.
Zhang
Fan
F
Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, People's Republic of China.
Lu
Ying-Jie
YJ
Wang
Shao-Xiong
SX
Sui
Sen-Fang
SF
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
D006023:Glycoproteins; D008563:Membrane Lipids; D010715:Phosphatidylglycerols; D010743:Phospholipids; D053482:beta 2-Glycoprotein I; D015978:Trichosanthin; C030345:1,2-dipalmitoylphosphatidylglycerol