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Article
The intrinsic pKa values for phosphatidylcholine and phosphatidylethanolamine in phosphatidylcholine host bilayers
Biophysical Journal
  • Frances C. Tsui, University of California, Los Angeles
  • David M. Ojcius, University of California, Merced
  • Wayne L. Hubbell, University of California, Los Angeles
ORCiD
David M. Ojcius: 0000-0003-1461-4495
Document Type
Article
DOI
10.1016/S0006-3495(86)83655-4
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.
Citation Information
Frances C. Tsui, David M. Ojcius and Wayne L. Hubbell. "The intrinsic pKa values for phosphatidylcholine and phosphatidylethanolamine in phosphatidylcholine host bilayers" Biophysical Journal Vol. 49 Iss. 2 (1986) p. 459 - 468 ISSN: 0006-3495
Available at: http://works.bepress.com/david-ojcius/225/