The intrinsic pKa values for phosphatidylcholine and phosphatidylethanolamine in phosphatidylcholine host bilayers
ORCiD
David M. Ojcius: 0000-0003-1461-4495
Department
Biomedical Sciences
Document Type
Article
Publication Title
Biophysical Journal
ISSN
0006-3495
Volume
49
Issue
2
DOI
10.1016/S0006-3495(86)83655-4
First Page
459
Last Page
468
Publication Date
2-1-1986
Abstract
Potentiometric titrations and surface potential measurements have been used to determine the intrinsic pKa values of both the carboxyl and amino groups of phosphatidylserine (PS) in mixed vesicles of PS and phosphatidylcholine (PC), and also of the amino group of phosphatidylethanolamine (PE) in mixed PE-PC vesicles. The pKa of the carboxyl group of PS in liposomes with different PS/PC lipid ratios measured by the two different methods is 3.6 +/- 0.1, and the pKa of its amino group is 9.8 +/- 0.1. The pKa of the amino group of PE in PE-PC vesicles, determined solely by surface potential measurements, is 9.6 +/- 0.1. These pKa values are independent of the aqueous phase ionic strength and of the effect of the liposome's surface potential due to the presence of these partially charged lipids.
Recommended Citation
Tsui, F. C.,
Ojcius, D. M.,
&
Hubbell, W. L.
(1986).
The intrinsic pKa values for phosphatidylcholine and phosphatidylethanolamine in phosphatidylcholine host bilayers.
Biophysical Journal, 49(2), 459–468.
DOI: 10.1016/S0006-3495(86)83655-4
https://scholarlycommons.pacific.edu/dugoni-facarticles/196
