Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162871 (abdominal aortic aneurysm)
 8,664 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eleven isoaccepting lysine tRNAs from mammalian sources are demonstrable by RPC-5 chromatography and polyacrylamide gel electrophoresis. The appearance and amounts of these isoacceptors varies with the source and growth state of cells. One isoacceptor, tRNALys6, observed in preparations of tRNA from some virus-transformed cells in culture, has been characterized by determining functional properties, cellular location, and its nucleotide sequence. tRNALys6 responds primarily to the lysine codon AAA, but it is not used efficiently in a wheat germ translational system in vitro. Compared with lysine isoacceptors 1, 2, 4, 5a, and 5, [3H]lysine appears in vivo in tRNALys6 with a delay of about 3 h. This delay may in part be a result of a less functional tRNA, but a compartmented state of tRNALys6 also appears to be important. tRNALys6 is associated with mitoplasts prepared from KA31 fibroblasts. The nucleotide sequence of tRNALys6 was determined by rapid postlabeling procedures involving limited hydrolysis in formamide, 32P-labeling of 5' ends of fragments with polynucleotide kinase, separation of the nested set of fragments in polyacrylamide denaturing gels, release of 5'-labeled nucleotides with RNase T2, and identification of the released nucleotides by chromatography on PEI cellulose. Confirmation of the positions of major nucleotides was done by using limited digestions by RNases of tRNALys6 labeled with 32P on the 3' terminus in a gel readout procedure. The nucleotide sequence of tRNALys6 differs from that of cytoplasmic lysine tRNAs and mammalian mitochondrial lysine tRNAs. It contains U*, an unidentified modified uridine occurring in the anticodon of some mitochondrial tRNAs. tRNALys6 appears to occur in very limited amounts, or not at all, in most cells unless stressed, but when present it is associated with mitochondria, although it is probably coded in the nucleus.
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PMID:Perturbation of the mitochondrial lysine tRNA population by virus-induced transformation or stress of mammalian cells: functional properties and nucleotide sequence of a mitochondrially associated lysine tRNA. 634 72

In this article, we report a full account of our recent development of pyrroles and N-alkoxyamides as new classes of nucleophiles for palladium-catalyzed AAA reactions, along with application of these methodologies in the total synthesis of agelastatin A, a marine natural product with exceptional anticancer activity and other biological properties. Our method allows for access to either regioisomer of the pyrrolopiperazinones (6 and 19) with high efficiency and enantioselectivity. Note that isomer 19 was obtained via a cascade reaction through a double allylic alkylation pathway. From regioisomer 6, the total synthesis of (+)-agelastatin A was completed in a very short fashion (four steps from 6), during the course of which we developed a new copper catalyst for aziridination and an In(OTf)(3)/DMSO system to oxidatively open an N-tosyl aziridine. Starting with the other pyrrolopiperazinone 19, a five-step sequence has been developed to furnish a formal total synthesis of (-)-agelastatin A. A unique feature of our syntheses is the use of two rather different strategies for the total syntheses of both enantiomers of agelastatin A using the same enantiomer of a chiral palladium catalyst.
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PMID:A stereodivergent strategy to both product enantiomers from the same enantiomer of a stereoinducing catalyst: agelastatin A. 1953 7