Tris salt vesicles

Some sustained release of bovine somatotropin was demonstrated fror liposome delivery systems. Egg phosphatidylcholine, ethanolamine an otocopheryl hemisuccinate, and Tris salt vesicles released bovine somato ropin, giving hypophysectomized rat growth for over a week (Janoff et al,... 

A polymeric stack of macrocycles has been synthesized [6.72] and a cyclodextrin-based model of a half-channel has been reported [6.73]. Channel-type conduction of Na+ ions has been reported for a tris-macrocyclic ligand [6.74]. A derivative of the acyclic polyether ionophore monensin forms lithium channels in vesicles [6.75a], which may be sealed by diammonium salts [6.75b]. 

One peripheral polypeptide with MW = 33 kDa is isolated with the PS II/OEC core (Table 1). Two other extrinsic peptides with molecular masses of 17 and 23 kDa have been implicated in the 02-evolving process, although they may be replaced in the core preparations by high concentrations of Ca " and CE salts with preservation of 02-evolution activity. The involvement of these three polypeptides in O2 evolution was first suggested by the Tris extraction experiments on so-called inside-out chloroplast vesicles by Akerlund et al. [71] and by cholate extraction of chloroplasts by Sayre and Cheniae [72]. A flurry of activity ensued and the situation with respect to these polypeptides is now reasonably clear. The biochemical properties of these polypeptides are discussed in detail in two recent reviews [7,8]. 

Fig. 18. Intermicellar (monomeric) bile salt concentrations (IMC) in TDC-L micelles and vesicle (liposome) systems as estimated by equilibrium dialysis. (Conditions pH 7, 2 mM Tris-maleate, 1 mM CaCl2, 150 mM NaCl, 0.2% NaNj, 25°C, starting [TDC] = 12 mM.) limit indicates phase limit of the TDC-L micellar phase, L/BS ratio represents the lipid ratio in the particles. (From ref. 6 with permission.)...

The vesicle dispersions were then treated with O.OlmM CUCI2 in the Tris buffer. A small precipitation was observed which dispersed upon vortex mixing. The unbound copper salt was removed by gel filtration on a sephadex G 75-125 column. Copper bound vesicles were then divided into two equal volumes. One portion was polymerized at 4°C by irradiating with 254 nm light for 10 minutes. 

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