Ion Transport Across Biological Membranes

Ionophores such as valinomycin also transport charged substrates across membranes. These often cyclic, low-molecular weight compounds do not 

Model systems have been developed for many of these ion-transport mechanisms in the context of bioorganic chemistry. Examples are the cyclic peptides, described by M. R. Ghadiri et al., that have antibiotic activity similar to that of ionophores, a property that is most probably caused by the ability of these peptides to self-assemble inside biological membranes into channels [1], Other compounds able to induce the formation of membrane pores are the bouquet-molecules introduced by J.-M. Lehn [2]. Artificial / -barrels have been developed by S. Matile s group [3]. Many host molecules used in bioorganic chemistry can serve as carriers for ions across membranes and have even made possible the development of systems with which active ion transport can be achieved [4]. 

Canceill, L. Jullien, L. Lacombe, J.-M. Lehn, Helv. Chim. Acta 1992, 75, 791-812 L. Jullien, T. Lazrak, J. Canceill, L. Lacombe, J.-M. Lehn, J. Chem. Soc., Perkin Trans 2 1993, 1011-1020. 

Bioorganic Receptors for Amino Acids and Peptides Combining Rational Design with Combinatorial Chemistry 

Carsten Schmuck, Wolfgang Wienand, and Lars Ceiger 

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Polyether antibiotics contain tetrahydrofuran rings. In monensin 11, three tetrahydrofuran rings are linearly connected. The molecule contains 17 asymmetric centres. Stereoselective syntheses for monensin have been elaborated [18]. In nonactin 12, the rings are interconnected in an a,a -orientation via ester groupings. Nonactin is therefore classed as a macrolide antibiotic. Polyethers of the type 11/12 are capable of facilitating ion transport across biological membranes they are, therefore, also known as ionophores. 

Chemical Kinetics, Experimentation Dielectric Gases Ion Transport Across Biological Membranes Kinetics (Chemistry) Mass Spectrometry Potential Energy Surfaces... 

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The feasibility of the carrier model for metal-ion transport across biological membranes has been explored by Lauger in terms of the known rate constants for the K+-valinomycin system. He makes an interesting comparison between the action of a carrier molecule and that of an enzyme. An enzyme... 

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