Dipalmitoyl phosphatidyl choline DPPC

The nomenclature for associating individual fatty acid groups with particular phosphodig-lyceride derivatives is straightforward. For instance, a phosphatidic acid (PA) derivative which contains two myristic acid chains is commonly called dimyristoyl phosphatidic acid (DMPA). Likewise, a PC derivative containing two palmitate chains is called dipalmitoyl phosphatidyl choline (DPPC). Other phosphodiglyceride derivatives are similarly named. 

We report here the results of a study of the adsorption of the alkaline earth cations to bilayer membranes formed from phosphatidylcholines with saturated chains dipalmitoyl phosphatidyl choline (DPPC) and dimyristoyl phosphatidyl choline (DMPC). Our salient result is that the adsorption of calcium is distinct from the other alkaline earth cations in two respects. First, only calcium adsorbs significantly more strongly to PCs with saturated chains than to phosphatidyl cholines with unsaturated chains, even when all lipids are present in the liquid crystalline state. Second, when the membranes are present in the frozen or gel state, the binding of calcium is significantly enhanced. We used two independent techniques to demonstrate this unique behavior of calcium. 

Before looking at the reconstituted membranes in more detail, we shall first discuss a simpler question concerning the distribution of ions in the aqueous phase of bilayer structures. Is the ion distribution in the water phase of typically 15 A width between the lipid surfaces homogenous, or is there a preferential binding to the polar head groups of the lipids These studies have been started in collaboration with G. Biildt and some preliminary results from dipalmitoyl phosphatidyl cholin (DPPC) membranes will be reported here. ... 

Recently, the competitive adsorption dynamics of phospholipid/protein mixed system at the chloroform/water interface was investigated by using the drop volume technique. The three proteins P-Lactoglobulin, P-Casein, and Human Serum Albumin were used in this study. To investigate the influence of the phospholipid structure at concentrations close to the CAC (critic aggregation concentration) the four lipids dipalmitoyl phosphatidyl choline (DPPC), dimyristoyl phosphatidyl choline (DMPC), dimyristoyl phosphatidyl ethanolamine (DMPE)... 

Abstract. Nonylphenyl-ethyleneoxide polymers containing 5, 9 and 30 ethyleneoxide groups per molecule build into the hydrophobic fatty acid chains of the cell membrane phospholipid dipalmitoyl-phosphatidyl-choline (DPPC) resulting in a decreased main transition temperature, a decreased enthalpy of the main transition and in enhanced potassium permeability of DPPC liposomes. The a-, jl- and y-cyclodextrins form inclusion complexes with the tenzides lowering their free concentration. The complex formation lessens or sometimes totally prevents the membrane damaging effect of tensides. The effectivity order of cyclodextrins is CD > yCD > aCD. 

In mammalian lipid interactions the structure and dynamics of sphingomyelin and dipalmitoyl-phosphatidyl-choline (DPPC) bilayers have been compared sterol-membrane interactions have been studied by comparative... 

Abbreviations for amino acids and their derivatives follow the revised recommendation of the lUPAC-IUB Committee on Biochemical Nomenclature, entitled Nomenclature and Symbohsm for Amino Acids and Peptides (recommendations of 1983). Nomenclature of branched polypeptides is used in accordance with the recommended nomenclature of graft polymers (lUPAC-lUB recommendations, 1984). For the sake of brevity codes of branched polypeptides were constracted by us using the one-letter symbols of amino acids (Table 1). The abbreviations used in this paper are the following. AK, poly[Lys-(DL-Ala )] AXK, poly[Lys-(DL-Ala -Xi)] XAK, poly[Lys(Xi-DL-Ala )] X = Ser (SAK), Om (OAK), Glu (EAK), or Ac-Glu (Ac-EAK). All amino acids are of L-configuration unless otherwise stated. DPH, l,6-diphenyl-l,3,5-hexatriene ANS, sodium anilino naphthalene sulfonate DPPC, dipalmitoyl phosphatidyl choline PG, phosphatidyl glycerol Z, benzyloxycarbonyl Pep, pentachlorophenol P, polarisation. 

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