On the noncatalytic proteins of membrane systems

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The conformational basis of energy conservation in membrane systems. II. Correlation between conformational change and functional states

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The conformational basis of energy transformations in membrane systems. I. Conformational changes in mitochondria

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Role of lipids in the structure and function of biological membranes

The concept of biological membranes as vesicular or tubular continua built up of nesting repeating units has been systematically explored and some of the relevant experimental work has been assembled. The bulk of the data have been drawn from studies on the mitochondrion, which is assumed to be a model for membranes generally. The repeating units of membranes are composite macromolecules containing both protein and lipid. The unit of the mitochondrial inner membrane is tripartite; the basepiece is the membrane-forming element. The four complexes of the electron transfer chain represent the different species of basepieces in the inner membrane. The repeating units of the outer mitochondrial membrane have a different form and size and a completely different set of enzymes (the enzymes of the citric and fatty acid oxidation cycles). The repeating units of the inner mitochondrial membrane are capable of forming membranes spontaneously. This membrane-forming capability is absolutely dependent on the presence of lipid. Evidence is presented for the view that lipid restricts the number of binding modalities and thus compels a two-dimensional alignment of repeating units. In absence of lipid three-dimensional stacking takes place, and the aggregates thus formed are, in effect, bulk phases. The membrane may be looked upon as a device for molecularizing repeating units, and it is this molecularization which underlies the essentiality of lipid for electron transfer. The theory of lipid requirement for enzymic activity is developed. The reconstitution of the electron transfer chain is shown to be essentially a membrane phenomenon rather than an expression of direct chemical interaction between the different parts of the electron transfer chain.

In vivo metabolism os chlorpromazine

The present state of our knowledge concerning the metabolism of CPZ in humans is as follows:

Non-polar metabolites — All eight of the postulated metabolites have been reported, with nor-CPZ-SO and bis-nor-CPZ-SO being present in the largest amounts and CPZ and CPZ-SO in lesser amounts.

Moderately polar metabolites — Only CPZ-NO is present in substantial amounts. We have detected two acidic, but non-basic, metabolites by TLC and tentatively identified them as N-β-carboxyethyl derivatives. The concentration of free phenols seems to be very low in fresh urine.

Highly polar metabolites — We have seen at least 15 glucosiduronides and/or sulfates by TLC.

The isolation of representative reference compounds from the highly polar fraction and the determination of their chemical structures will permit the development of analytical techniques for their routine estimation. This information may disclose differences in the metabolic patterns of different patients and may permit the correlating of drug responsiveness with specific metabolic processes.

Obviously, the finding of any anomalous metabolism could have many consequences: it might provide a means of understanding why some patients are drug-responders while others are drug-refractory. Also, vitamins, coenzymes, or other substances which are known to have a role in that particular type of metabolic reaction could be used in an attempt to modify the action of the currently used phenothiazines. Finally, if a certain metabolic pathway is found to lead to either especially high or especially low therapeutic efficacy, medicinal chemists could ‘tailor-make’ a molecule which either facilitates or blocks that particular metabolic sequence in order to improve the clinical usefulness of the phenothiazine ‘tranquillizers’.

Membranes as expressions of repeating units

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