Localization domains

We have previously shown that a 209 amino acid region (aa288-497, asymmetric localization domain) of Insc is necessary and sufficient for apical cortical localization and for mitotic spindle orientation along the apical-basal axis (Tio et al 1999). In a yeast two-hybrid screen we identified Partner of Inscuteable (Pins), a novel 658aa protein with multiple repeats of the Tetratricopeptide (TPR) motif. Affinity purification experiments using embryonic extracts demonstrate that Pins complexes with Insc in vivo. In vitro protein interaction assays demonstrates that Pins interacts with the Insc asymmetric localization domain (see Yu et al 2000). 

We can see now why the static model of Lewis with four electron pairs in a tetrahedral arrangement is so useful even though electrons are in rapid motion and do not occupy fixed positions. Each electron pair occupies a reasonably well localized domain, and four domains have a tetrahedral arrangement. 

The photo-oxidation of a solid branched alkane can be expected to proceed in localized domains, new oxidation chains being generated from the photo-cleavage of -00H products, and chain propagation (reactions 2 and 3) being concentrated close to each initial site in a given domain to produce a zone of high -00H concentration. Thus the distribution of an additive in and around these domains is of special importance. 

Structure and mobility of adsorbed molecules may exhibit a wide spectrum of features. As a general view it is commonly accepted that layers are formed on increasing abundance. The mobility of molecules in the first layer depends strongly on interactions present in a given case. Local domains of adsorbed molecules may be formed in the case of non-uniform surface. Analysis of deuteron spectra for a series of molecules adsorbed on neutral alumina led to the conclusion that while the exchange of molecules between layers in a given domain is fast, the diffusion rate between domains is slow [5],... 

Blaustein But you get a Ca2+ wave. In the vascular smooth muscle no Ca2+ waves occur from this. There is a clear hyperpolarization that results from actions at the local domain, where Ca2+ release triggers the activation of the BK channel. 

Domains may be regarded as the basic units for the structure, function and evolution of proteins, but the definition of a domain remains fuzzy. They are most often treated as compact or connected areas that are apparent from a visual inspection of protein models. To avoid subjectivity and ambiguities of visual inspection, computer algorithms have been developed to localize domains. Rashin offered an alternative interpretation domains are stable globular fragments, generated in biochemical experiments that refold autonomously and retain specific functions. He proposed a method for localiz-... 

When a phase transition occurs from a pure single state and in the absence of wettable surfaces the embryogenesis of the new phase is referred to as homogeneous nucleation. What is commonly referred to as classical nucleation theory is based on the following physical picture. Density fluctuations in the pre-transitional state result in local domains with characteristics of the new phases. If these fluctuations produce an embryo which exceeds a critical size then this embryo will not be dissipated but will grow to macroscopic size in an open system. The concept is applied to very diverse phenomena ... 

The importance of single-bond conformation is nevermore apparent than for polypeptides. Here, distinct local domains involving a-helices and P-sheets (among other structures) occur commonly, and these in turn dictate overall (tertiary) stmcture of proteins and ultimately protein function. Interestingly, proteins appear to exhibit well-defined shapes, that is, exist as a single conformer or a very few closely-related conformers. This is the reason that they can be crystallized and their structures determined, and is certainly a major factor behind the ability of proteins to direct specific chemical reactions. 

Siomi,H. andDreyfuss, G. (1995) A nuclear localization domain in the hhRNPAl protein. J. CellBiol., 129, 551-560. 

The first series of design points-trials of a basic design is preceded by numerous activities meant to select the local domain of factor space. Thereby, limits of factors space that in principle determine the limitations, technoeconomic possibilities and concrete conditions for doing the process, are being estimated. The factor space requires careful analysis of preliminary information on the scope of response change and on curvature of the response surface. 

Fig. 32 shows on the left a conventional, localized domain model of the electronic environment of an atom that satisfies the Octet Rule. Each domain is occupied by two electrons. It is well known, however, that the assumption of two electrons per orbital is unnecessarily restrictive 27>122>. Better energies are obtained in quantum mechanical calculations if different orbitals are used for electrons of different spins, a fact first demonstrated in quantitative calculations on helium by Hylleraas 123> and Eckart 124>. Later, this "split-orbital method was applied to 71-electron systems 27,125) Its general application to chemical systems has been developed by Linnett 126>. 

Hunziker W, Mellman I. Expression of macrophage-lymphocyte Fc receptors in Madin-Darby canine kidney cells polarity and transcytosis differ for isoforms with or without coated pit localization domains. / Cell Biol 1989 109(6 Pt 2) 3291-302. 

The local domains of connections between fragment A and the rest B of the molecule AB are defined as... 

Using this approach, new local domain types appear at those locations of the molecular electron density where the region R connects to the rest M of the molecule RM = M ... 

Let us consider an electromagnetic field given within a local domain V, bounded by the surface S. In the frequency domain, this field satisfies equations (8.102) and (8.103)... 

Wc now examine the solution of Maxwell s equation in an unbounded domain with the given distribution of electromagnetic parameters e, //, and electromagnetic field is generated by the sources (extraneous currents j ), concentrated within some local domain Q. Using the energy inequality (8.112), we can prove that there is only one (unique) solution of this problem. 

Ob- Within this chapter we will confine ourselves to consideration of nonmagnetic media and, hence, assume that /x = /tg = drr x 10 ///m, where is the free-space magnetic permeability. The model is excited by an electromagnetic field generated by an arbitrary source with an extraneous current distribution j concentrated within some local domain Q. This field is time harmonic as Complex conductivity... 

Let us consider the case of a homogeneous isotropic elastic medium within a local domain V, bounded by the surface S. Various physical processes may take place on the boundary of the domain V and in the space around it. For example, the oscillation energy can flow freely through the boundary, or energy can stay within the domain, being reflected from the boundary 5, etc. Therefore to make the problem of wavefield propagation of the initial disturbance mathematically specific, we also should determine the boundary conditions of the oscillations of the elastic medium. This condition is called a boundary-value condition. 

Secondly, we can use the known fact that the disturbance (the displacement field) propagates in the elastic medium with a finite velocity. This means that if the disturbance is local at initial moment of time to (U (r, to) 7 0 only within some local domain), then it will be contained within a sphere of some finite radius r at any subsequent moment. The same observation holds true for the difference field U (r, t) as well. Therefore, considering the difference displacement field U (r, t) at some specified moment of time t > to, one can select an auxiliary sphere of the radius r large enough for the integral over the sphere Or in formula (13.154) to be equal to zero. From here, as it was previously discussed in the case of the bounded domain, it follows that relation (13.153) holds true, and the solution of the corresponding initial-value problem is unique. 

Figure 14-1 Separation of the acoustic wavefield into incident and scattered (background and anomalous) parts. The external source is located within some bounded domain Q. The wavespeed is equal to the background velocity everywhere with exception of the local domain D where the velocity is different from the given background values.

Frechet derivative for the elastic forward modeling operator Let us assume that the Lame velocities are known and fixed everywhere in space with the exception of some local domain D. We can find the equations for the Frechet derivative by applying the variational operator to both sides of the corresponding Lame equation (15.230)... 

Figure 5 equally displays the localization domains of aniline determined using the electron localization function technique (ELF)12,64, which defines the electronic basins within a molecular system. The basins correspond to the domains where electrons are localized either in paired bonds or in nonbonding lone pairs. In such a way, the number and nature of bonds between atoms could be determined. The ELF r)(r) value varies from 0 to 1 (0 < rj(r) < 1), which is chosen to determine the isosurfaces of the domains. Basins can be classified according to their synaptic order, that is, monosynaptic basins belong to the cores (denoted by C) whereas disynaptic basins describe the valence regions (denoted by V). 

As in the case of phenol or monosubstituted benzenes12, ANI exhibits six C(C) and one C(N) core basins, six V(C,C), five V(C,H), one V(C,N), two V(N,H) and one V(N, lone pair) localization domains. Integration of the density over each domain allows the amount of electrons present there to be determined. Thus the C—C bonds are nearly equivalent and each V(C,C) basin classically contains about 2.7-2.9 electrons (close to 3.0), whereas the V(N) and V(C,N) basins have 1.8 and 1.9 electrons, respectively (Figure 5). Relative to benzene, an increase in the population of the V(Cor//1<>—Cm< M) basin is noticeable (0.1 e) whereas the populations of other domains remain almost unchanged. Overall, the above analysis is in line with the classical picture that chemists always have about the electron distribution in aniline. 

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