Post by skyship on Apr 30, 2014 18:35:40 GMT -5
Again, lets look at this:
protein/polymer hybrids
Bioorthogonal chemistry:
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non canonical: are......
Non-proteinogenic amino acids
en.wikipedia.org/w/index.php?title=Non-canonical_amino_acids&redirect=no
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Non-coded, non-proteinogenic, or unnatural amino acids are those not naturally encoded or found in the genetic code. Despite the use of only 23 amino acids (21 in eukaryotes) by the translational machinery to assemble proteins (the proteinogenic amino acids), over 140 natural amino acids are known and thousands of more combinations are possible.
Several non-proteinogenic amino acids are noteworthy because they are:
intermediates in biosynthesis
post-translationally incorporated into protein
possess a physiological role (e.g. components of bacterial cell walls, neurotransmitters and toxins)
natural and man-made pharmacological compounds
present in meteorites and in prebiotic experiments (e.g. Miller–Urey experiment)
..........The genetic code encodes 20 standard amino acids. However, there are three extra proteinogenic amino acids: selenocysteine, pyrrolysine and N-formylmethionine. The former two do not have a dedicated codon, but are added in place of a stop codon when a specific sequence is present, UGA codon and SECIS element for selenocysteine, UAG PYLIS downstream sequence for pyrrolysine.[2][3] Formylmethionine is an amino acid encoded by the start codon AUG in bacteria, mitochondria and chloroplasts, but is often removed posttranslational...........
en.wikipedia.org/wiki/Non-proteinogenic_amino_acids
Several non-proteinogenic amino acids are noteworthy because they are:
intermediates in biosynthesis
post-translationally incorporated into protein
possess a physiological role (e.g. components of bacterial cell walls, neurotransmitters and toxins)
natural and man-made pharmacological compounds
present in meteorites and in prebiotic experiments (e.g. Miller–Urey experiment)
..........The genetic code encodes 20 standard amino acids. However, there are three extra proteinogenic amino acids: selenocysteine, pyrrolysine and N-formylmethionine. The former two do not have a dedicated codon, but are added in place of a stop codon when a specific sequence is present, UGA codon and SECIS element for selenocysteine, UAG PYLIS downstream sequence for pyrrolysine.[2][3] Formylmethionine is an amino acid encoded by the start codon AUG in bacteria, mitochondria and chloroplasts, but is often removed posttranslational...........
en.wikipedia.org/wiki/Non-proteinogenic_amino_acids
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The term bioorthogonal chemistry refers to any chemical reaction that can occur inside of living systems without interfering with native biochemical processes. The term was coined by Carolyn R. Bertozzi in 2003. Since its introduction, the concept of the bioorthogonal reaction has enabled the study of biomolecules such as glycans, proteins, and lipids in real time in living systems without cellular toxicity. A number of chemical ligation strategies have been developed that fulfill the requirements of bioorthogonality, including the 1,3-dipolar cycloaddition between azides and cyclooctynes (also termed copper-free click chemistry), between nitrones and cyclooctynes,[8] oxime/hydrazone formation from aldehydes and ketones, the tetrazine ligation, the isonitrile-based click reaction, and most recently, the quadricyclane ligation.
The use of bioorthogonal chemistry typically proceeds in two steps. First, a cellular substrate is modified with a bioorthogonal functional group (chemical reporter) and introduced to the cell; substrates include metabolites, enzyme inhibitors, etc. The chemical reporter must not alter the structure of the substrate dramatically to avoid affecting its bioactivity. Secondly, a probe containing the complementary functional group is introduced to react and label the substrate.
en.wikipedia.org/wiki/Bioorthogonal_chemistry
The use of bioorthogonal chemistry typically proceeds in two steps. First, a cellular substrate is modified with a bioorthogonal functional group (chemical reporter) and introduced to the cell; substrates include metabolites, enzyme inhibitors, etc. The chemical reporter must not alter the structure of the substrate dramatically to avoid affecting its bioactivity. Secondly, a probe containing the complementary functional group is introduced to react and label the substrate.
en.wikipedia.org/wiki/Bioorthogonal_chemistry
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Bioorthogonal chemistry in living organisms
Bioorthogonal chemistry allows for selective and efficient modification of biomolecules in their natural environment. Several strategies have been developed over the past years that employ cellular biosynthetic pathways to incorporate the desired functionalities. These moieties in turn efficiently react with exogenously added complementary reaction partners. This field has now moved forward from a conceptual phase to the application of these methodologies in living systems. In this perspective, we highlight recent and exciting developments pertaining to the use of bioorthogonal chemistry in living organisms. pubs.rsc.org/en/content/articlelanding/2013/sc/c3sc52768a#!divAbstract[/quote]
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