Structure-function relationship, study

Protein chemical modification is a problem-solving technique in research and technology. Modifications also occur in natural deteriorations. Generally these modifications are with the most reactive side chains and are predominantly oxidations, reductions, and nucleophilic and electrophilic substitutions. Deteriorations include peptide bond scissions, racemizations, fi-eliminations, and formation of products by the reaction of proteins with added chemicals. Proteins are modified intentionally for structure-function relationship studies or for development of new and improved products. Although appearing quite varied, the techniques used in pharmacological, food and feed, or other industrial areas differ more operationally than from major differences in the levels of chemical sophistication that are used. 

A structure function relationship study by (Gamblin et al., 2000) points out that tau contains very few predicted structural elements, but these small structural units, whether predicted or measured through biochemical/biophysical methods, are likely... 

Prior to the detailed crystallographic studies of hPL a considerable amount of biochemical data relating to the activation mechanism of hPL had been accumulated. hPL is the only lipase among the lipases with known X-ray structures for which systematic structure-function relationship studies have been initiated using site-directed mutagenesis (Lowe, 1992). Substitutions were made at positions Ser-153, His-264, and Asp-177, and measurements of catalytic activity and interfacial binding were carried out. These studies showed that the catalytic site is... 

The /r-conotoxins have been used substantially as probes to gain greater understanding of Na channel structure-function relationships. Studies using GIIIA demonstrated that the four repeats within the a-subunit of all Na" " channels have a clockwise orientation. ... 

Jarnagin, A.S. and Ferrari, E. (1992) Extracellular enzymes gene regulation and structure function relationship studies. Biotechnology, 22, 189-217. 

Structure— Function Relationships. Since PCBs and related HAHs are found in the environment as complex mixtures of isomers and congeners, any meaninghil risk and hazard assessment of these mixtures must consider the quaUtative and quantitative stmcture—function relationships. Several studies have investigated the stmcture—activity relationships for PCBs that exhibit 2,3,7,8-tetrachlorodibenzo-p-dioxin [1746-01-6] (1)... 

RNA structures, compared to the helical motifs that dominate DNA, are quite diverse, assuming various loop conformations in addition to helical structures. This diversity allows RNA molecules to assume a wide variety of tertiary structures with many biological functions beyond the storage and propagation of the genetic code. Examples include transfer RNA, which is involved in the translation of mRNA into proteins, the RNA components of ribosomes, the translation machinery, and catalytic RNA molecules. In addition, it is now known that secondary and tertiary elements of mRNA can act to regulate the translation of its own primary sequence. Such diversity makes RNA a prime area for the study of structure-function relationships to which computational approaches can make a significant contribution. 

Kerbiriou D, Griffin J Human high molecular 27 weight kininogen. Studies of structure-function relationships and of proteolysis of the molecule occurring during contact activation of plasma. J Biol Chem 1979 245 12020-12027. 

Historically the Shaker (Sh) K channel was the first K channel which was cloned and characterized [6-10]. Subsequently many more channel cDNAs and genes have been isolated and studied. Yet Sh channels remained in the forefront of channel research. The study of Sh channel mutants has provided the most thorough insight into structure-function relationships of K channels to date. I will first discuss in this chapter the primary sequences of voltage-gated channels. I will only use a few selected examples for discussion. As of this time, so many related K channel protein sequences have been published that it is not feasible to discuss all of them. Subsequently, I will describe in detail the present knowledge about functional K" " channel domains which are implicated in activation, inactivation and selectivity of the channel. 

Fabrication approaches have been previously used in two-dimensional (2D) micropattemed model systems and have led to insights on the effect of cell-cell and cell-polymer scaffold interactions on hepatocyte and endothelial cell fate. Extending these studies, the application of 3D fabrication techniques may also prove useful for studying structure-function relationships in model tissues. 

Extensive biochemical and spectroscopic studies have been undertaken on hCP in order to investigate the nature of the copper centers and their role in structure-function relationships. However, the protein is very susceptible to aggregation, proteolysis, loss of copper, and other chemical degradations and requires careful preparation and handling in these circumstances it is difficult to review all the literature objectively and comprehensively. A three-dimensional crystal structure of hCP has been reported at a nominal resolution of 3.1A [7], but this resolution has been extended to just beyond 3.0 A. This chapter will summarize some of the more important biochemical and spectroscopic studies of the protein. It will then focus on the structural results recently obtained by X-ray crystallographic methods and attempt to explain putative functions of the protein in terms of its molecular structure. 

Application of vibrational spectroscopy to the study of structure-function relationship in Langmuir-Blodgett films... 

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