Overall similarity

Many reduced heteroaromatic compounds are important and are dealt with in the General Chapters and appropriate Monograph Chapters, but usually more briefly than for the corresponding heteroaromatic systems because of this overall similarity with the corresponding acyclic compounds. 

On many occasions, new equipment is installed or process workers have to work in other similar plant units in order to substitute for one of their colleagues. Despite the overall similarity of the new equipment, there might be some differences in their operation which may sometimes become very critical. We caimot always rely on the operator to discover these potentially critical differences in equipment design, especially under time pressure and excessive workload. If multiskill training in a range of plant equipment is not feasible, then training should be provided for the specific new equipment. The incident below was due to lack of training for a caimed pump. 

The structural features are reflected in the characteristic properties of inorganic glasses and bring about a broad overall similarity in behaviour as summarised below. Values for the physical properties of the commercial glasses listed in Table 18.3 are given in Table 18.4. 

It has been suggested that the transformations accomplished by the brown-rot fungus Gleophyllum striatum may involve hydroxyl radicals, and this is supported by the overall similarity in the structures of the fungal metabolites with those produced with Fenton s reagent (Wetzstein et al. 1997). 

These eukaryotic glutamate transporters form a family that displays approx 50% overall identity and approx 60% overall similarity and is distinct from the GABA and norepinephrine transporter family. The eukaryotic glutamate transporters are also... 

The first zinc enzyme to be discovered was carbonic anhydrase in 1940, followed by car-boxypeptidase A some 14 years later. They both represent the archetype of mono-zinc enzymes, with a central catalytically active Zn2+ atom bound to three protein ligands, and the fourth site occupied by a water molecule. Yet, despite the overall similarity of catalytic zinc sites with regard to their common tetrahedral [(XYZ)Zn2+-OH2] structure, these mononuclear zinc enzymes catalyse a wide variety of reactions, as pointed out above. The mechanism of action of the majority of zinc enzymes centres around the zinc-bound water molecule,... 

This result is approximately independent of the size of T given that Q is an approximate subset of T. A comparable selection of molecules would not be obtained using the symmetric similarity coefficient in Eq. 2.19 or the asymmetric similarity coefficient given by Eq. 2.27 because as the target molecule increased in size the denominator would reduce the overall similarity values making selection less likely. If, on the other hand, Q is a relatively large, that is, if IQ I I T, then using the lower expression for asymmetric similarity in Eq. 2.27 will produce similar results... 

Similarity indices corresponding to different fields can be combined into an overall similarity index, for example,... 

El Bakali et al. noted an overall similarity between the chemistry of benzene and the chemistry of toluene, based on their oxidation mechanisms. Ethylbenzene has also been the subject of mechanistic studies,most recently by Ergut et al. ... 

Thus, although the nmr methods are important for comparison of the structure of proteins in the solid state and in solution, they are also of importance in areas where X-ray crystallography can provide little information. One of these areas concerns the time dependence of protein structure, for molecular motion over a wide range of time scales can be detected. Table IV indicates the methods and references to these studies. The range of the nmr technique is from about 10 10 s to slower than 10 s. Thus, although more restricted than X-ray crystallography in direct structure determination, the nmr studies can check the solution structure and complement the diffraction studies once the overall similarity between the solid and solution structure is proved. In this way nmr relates the static picture of a protein structure to the kinetic data of solution chemistry. 

What then is the drug designer to do, in order to achieve selectivity, in the face of overall similarity between receptor sites Two knowledge-based approaches have been used, and therefore come within our definition of drug design. Both approaches rely heavily on computational techniques, and on a principle that increased selectivity will parallel increased affinity for the receptor of interest. 

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