Sequence-chemical structure relationships

There are several difficulties in searching for sequence-chemical structure relationships. There is no available computer algorithm for detecting a sequence similarity among three sequences or more (, 45). We can search for sequence similarity only between a pair of sequences. Most sequence similarities found between the... 

Here we skim over the field of semiempirical VB theory of the Jt-systems of benzenoids. Primary focus is on a systematic derivational development of a hierarchical sequence of VB models. Different VB-based models are addressed in different sections (2, 3,5, 6) here, and the overall development is summarized in the diagram at the conclusion of Sect. 7. Section 4 serves as an interlude on quantum chemical computational methods, with emphasis on the VB basis and its relationship to chemical structure — this being crucial for the following sections. Along the way we indicate some of the history and general characteristics of the models. The unifying view which emerges not only incorporates many aspects of past work but reveals avenues for future research. 

For example, papers describing previously unreported syntheses or reaction sequences, structure-activity relationships, or newly discovered chemical compounds make good use of chemical structure images. Simple chemical struc-... 

In addition to these elementary motions, the C T measurements have shown that a much faster anisotropic motion occurs, correjgondlng to a libration motion of the CH bonds inside a cone. Recent C Tj measurements ( 10 ) performed on bulk polybutadiene containing both cis 1,4 and trans 1,4 sequences have shown a lower mobility of the trans sequences relatiy to the cis units. This result illustrates the main interest of studies, allowing one to reach more detailed information on the dynamics of each group in the polymer chain and thus yielding a way of setting up a relationship between the chemical structure and the dynamic behavior of bulk polymers. 

The Purohit and Stem oligonucleotide is relatively small, it contains a fairly extensive secondary stmcture, and the chemical protection data provide a substanti body of data on the exposure of several of the bases. As a consequence, this molecule falls into the class where reasonable predictions can be made about the three dimensional structure. Given the importance of the decoding site, such predictions can suggest sequence-structure relationships that might be tested experimentally. 

The chemical structure of penicillin-amido-p-lactam hydrolases from different bacteria has been studied by amino-acid sequence determinations. A genetic relationship among different bacterial genera was unveiled Sa... 

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