Ammonium sulfate transmembrane

Doxil , of which I had the pleasure of being one of the inventors (1-12), serves as an example of successful passive targeting to tumors in animals and humans (1,3,4,13). The ammonium sulfate (AS) transmembrane inside high/outside low gradient-driven loading is also the basis for doxorubicin (DOX) loading for Targeted Doxil (14), which soon will be tested in clinical trials. 

Figure 1 Facing page) (A) Mechanism of remote loading of doxorubicin by transmembrane ammonium sulfate gradient. (B) Collapse of transmembrane ammonium ion gradient in SSL by nonactine induces doxorubicin release. (C) Collapse of transmembrane proton gradient in SSL by nigericin induces collapse of transmembrane ammonium ion gradient followed by release of DOX. Abbreviations. DOX, doxorubicin SSL, sterically stabilized liposome.

Table 2 Characterization of 100nm SSL Remote Loaded with DOX via Transmembrane Ammonium Sulfate Gradient ... 

Table 3 Comparison Between 100-nm SSL Remote-Loaded with DOX via Higher Inside/Lower Outside Transmembrane Gradients of Either 250 mM Ammonium Sulfate or of Ammonium Glucuronate...

Haran G, Cohen R, Bar LK, Barenholz Y. Transmembrane ammonium sulfate gradients in liposomes produce efficient and stable entrapment of amphipathic weak bases. Biochim Biophys Acta 1993 1151 201-215. 

Zhigaltev FV, Kaplun AP, Kucheryanu VG, et al. Liposomes containing dopamine entrapped in response to transmembrane ammonium sulfate gradient as carrier system for Dopamine delivery into the brain of Parkinsonian mice. J Liposome Res 2001 11 55-71. 

Zhigaltsev, I. V., Kaplun, A. P, Kucheryanu, V. G., Kryzhanovsky, G. N., Kolomeichuk, S. N., Shvets, V. I., and Yurasov, V. V. (2001), Liposomes containing dopamine entrapped in response to transmembrane ammonium sulfate gradient as carrier system for dopamine delivery into the brain of parkinsonian mice, J. Liposome Res., 11,55-71. 

The ATPase complex of chloroplasts (H -ATPase, ATP-synthase) carries out synthesis (hydrolysis) of ATP coupled with transmembrane transport of hydrogen ions. This complex consists of a hydrophylic catalytic part called coupling factor CF, and a hydrophobic part, CFq, the function of which is to translocate protons towards CF. CFj can bind as many as six nucleotide molecules / /. After CF precipitation by ammonium sulfate with subsequent gel filtration, the enzyme retains about 1 mol of tightly bound nucleotides consisting mainly of ADP /2/. 

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