Download or read book Applications of an Expanded Genetic Code written by Eric M. Brustad and published by ProQuest. This book was released on 2008 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an ever expanding genetic code it is no longer a question of whether an unnatural amino acid can be introduced into a protein sequence, but what can be done with them. This thesis describes the introduction of novel amino acids to the genetic codes of E. coli and yeast and the applications of those amino acids towards novel protein biochemistry and the study of biomolecular structure and function. This includes the development of orthogonal protein labeling strategies that allow the site-specific attachment of biophysical probes and other molecules onto a protein surface. An unnatural ketone containing amino acid is described that allows the general and efficient introduction of fluorophores and spin probes onto a protein surface. This chemistry is exploited for the site-specific double labeling of proteins with fluorophores and the utility of this methodology is demonstrated by the examination of bacteriophage T4 lysozyme folding via single molecule fluorescence energy transfer. To expand the orthogonal chemistry presented by unnatural amino acid mutagenesis, the addition of a boronic acid containing amino acid to the genetic code of E. coli is also described. The unique chemistry of this functionality is exploited for the site-specific labeling of proteins with fluorophores through Suzuki coupling reactions as well as the formation boronic esters with diol containing compounds. This latter chemistry is also useful for the genetic encoding of carbohydrate recognition into a protein sequence as well as the development of a single step scarless protein purification methodology. The evolution of the E. coli leucyl tRNA synthetase for the site-selective introduction of methionine, cysteine and alanine analogs into proteins in yeast is also described. From this work, a single tRNA synthetase that shows promiscuous activity for over ten unnatural amino acid structures is investigated. Finally, a project investigating the role and source of reactive oxygen species in cytokine signaling is also be briefly discussed.