Dipalmitoylphosphatidic acid

Log D, log P at pH = 7.4 IC5o, concentration for Ca2 displacement from dipalmitoylphosphatidic acid (DPPA) monolayers. 

Phase separation is observed when mixtures of phospholipids are incorporated into the membrane where the single components possess certain differences in their structure. In this case the phase separation is indicated in the thermogram by two or more signals. Structural characteristics which could lead to phase separation are differences in chain length and different degrees of saturation. Mixtures of dipalmitoylphosphatidic acid (DPPA) and diphosphatidylcholine (DPPC) or of distearoyllecithin with dimyristoyllecithin, for example, show the phenomena of phase separation. The reason for this is a lateral phase separation caused by domain formation. 

Abbreviations DMPC, DPPC, DSPC, dimyristoyl-, dipalmitoyl-,distearoyl-phosphatidylcholine DPPA, dipalmitoylphosphatidic acid PE, phosphatidylethanolamine PS, phosphatidylserine (U) and (M), unilamellar and multilamellar liposomes temperature of crystal liquid-crystal transition Diff. spectr., difference spectroscopy. 

Hexadecanoic acid 1 -[(phosphonoxy)methyl]-l,2-eth anediyl ester, 9CI. Dipalmitoylphosphatidic acid [19698-29-4]... 

Dipalmitoyl-5/i-glyccro-L-serine, in G-00045 Dipalmitoylphosphatidic acid, see G-00040 Dipalmitoylphosphatidylcarnitine, D-00175 Dipalmitoylphosphatidylcholine, see G-00041 Dipalmitoylphosphatidylethanolamine, see... 

A slow reorganization was reported to occur upon addition of amphiphilic polymers to a system of small vesicles of DPPC/DPPA (dipalmitoylphosphatidic acid) that resulted in mixed aggregates of micellar size. The added polymers were poly(sodium acrylate/isopropylacrylamide) bearing some pendant hydrophobic alkyl chains with 8 or 18 carbon atoms. The change of vesicle hydrodynamic radius with time was biphasic... 

Sensitivity of stationary ATR measurements Commercial multiple internal reflection elements MIRE permit up to 50 internal reflections. This is generally enough for thin-layer spectroscopy in the nanometre or even subnanometre region. As an example. Figure 9 shows a dipalmitoylphosphatidic acid monolayer, i.e. a lipid monolayer of about 2 nm thickness, which has been transferred from the air-water interface to a germanium MIRE by means of the Langmuir-Blodgett technique. 

Figure 9 Parallel ( ) and perpendicular (X) polarized ATR absorbance spectra of a dipalmitoylphosphatidic acid (DPPA) monolayer transferred at 30 mN m from the aqueous subphase (10 M CaCl2) to a germanium multiple internal reflection element (MIRE). Spectra were obtained from the dry monolayer in contact with dry air. A surface concentration of r = 3.93 x 10" mol cm- was calculated by means of Equation [36] using the dichroic ratio of the symmetric CHj stretching vibration at 2850 cm" with respect to a linear baseline (B), resulting in [v (CH2)j = 0.923. Angle of incidence 0, = 45° number of equal functional groups v = 28 number of active internal reflections A/ = 39.

---