Domain shapes, complex forms

The structure of the binary complex formed between a-actin and CCT has also been examined by cryoelectron microscopy (Llorca et al., 1999a Marco et al., 1994). This revealed that actin binds within the CCT cavity as a rod-shaped mass attached at either end to the apical domains of two... 

It is possible to produce extended areas of homeotropically-aligned smectic phases, but when the mesophase is formed by cooling from the melt on an unprepared surface, a disordered pattern of distinct domains is usually formed. Textures of this kind are known as focal conics because of the geometry of the basic structural units. These are formed by stacking concentric, curved, cooling-tower shaped layers inside each other like Russian dolls (Fig. 1.21). The reason why such an apparently complex structure of this kind arises spontaneously is not immediately obvious, but... 

Figure 6.21 Schematic diagram of the conformational changes of calmodulin upon peptide binding, (a) In the free form the calmodulin molecule is dumhhell-shaped comprising two domains (red and green), each having two EF hands with bound calcium (yellow), (b) In the form with bound peptides (blue) the a helix linker has been broken, the two ends of the molecule are close together and they form a compact globular complex. The internal structure of each domain is essentially unchanged. The hound peptide binds as an a helix.

The proposed model for the so-called sodium-potassium pump should be regarded as a first tentative attempt to stimulate the well-informed specialists in that field to investigate the details, i.e., the exact form of the sodium and potassium current-voltage curves at the inner and outer membrane surfaces to demonstrate the excitability (e.g. N, S or Z shaped) connected with changes in the conductance and ion fluxes with this model. To date, the latter is explained by the theory of Hodgkin and Huxley U1) which does not take into account the possibility of solid-state conduction and the fact that a fraction of Na+ in nerves is complexed as indicated by NMR-studies 124). As shown by Iljuschenko and Mirkin 106), the stationary-state approach also considers electron transfer reactions at semiconductors like those of ionselective membranes. It is hoped that this article may facilitate the translation of concepts from the domain of electrodes in corrosion research to membrane research. 

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