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排序方式: 共有206条查询结果,搜索用时 593 毫秒
41.
Tyrell R. Towle Chaitanya A. Kulkarni Lisa M. Oppegard Bridget P. Williams Taylor A. Picha Hiroshi Hiasa Robert J. Kerns 《Bioorganic & medicinal chemistry letters》2018,28(10):1903-1910
Structural studies of topoisomerase-fluoroquinolone-DNA ternary complexes revealed a cavity between the quinolone N-1 position and the active site tyrosine. Fluoroquinolone derivatives having positively charged or aromatic moieties extended from the N-1 position were designed to probe for binding contacts with the phosphotyrosine residue in ternary complex. While alkylamine, alkylphthalimide, and alkylphenyl groups introduced at the N-1 position afforded derivatives that maintained modest inhibition of the supercoiling activity of DNA gyrase, none retained ability to poison DNA gyrase. Thus, the addition of a large and/or long moiety at the N-1 position disrupts ternary complex formation, and retained ability to inhibit supercoiling is likely through interference with the strand breakage reaction. Two derivatives were found to possess inhibitory effects on the decatenation activity of human topoisomerase II. 相似文献
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Annexins (or lipocortins) are a family of at least 10 structurally related calcium- and phospholipid-binding proteins. Each protein consists of a conserved core domain having four (or eight) repeats of a segment approximately 70 amino acids in length and a nonconserved, usually short, amino-terminal domain. To date, amino acid sequences for eight distinct mammalian annexins have been predicted from cDNAs. This report describes an additional member of this family, bovine annexin XI, identified by cDNA cloning and sequence analysis. The 503-amino acid deduced protein consists of a core domain of four annexin repeats and a long amino-terminal domain rich in glycine, proline, and tyrosine. This novel annexin gene is expressed in a wide variety of tissues and isolated cells in culture. 相似文献
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A large-subunit mitochondrial ribosomal DNA sequence translocated to the nuclear genome of two stone crabs (Menippe) 总被引:1,自引:0,他引:1
Two DNA sequences that appear to be homologous to large-subunit
mitochondrial ribosomal RNA genes have been identified in the stone crabs
Menippe mercenaria and M. adina. Amplification from whole genomic DNA by
polymerase chain reaction (PCR) with oligonucleotide primers based on
conserved portions of large-subunit mitochondrial rRNA genes consistently
amplified two products of similar length (565 and 567 bp). These products
differed at 3% of their nucleotide bases, and could be distinguished by a
HindIII site. Only one of these sequences (designated the A sequence) was
detected by PCR in purified mitochondrial DNA. The other (designated the B
sequence) hybridized to total genomic DNA at a level consistent with a
nuclear genome location. It is unlikely that the type B product would have
been recognized as a nuclear copy by examination of its sequence alone.
This is the first report of a mitochondrial gene sequence translocated into
the nuclear genome of a crustacean.
相似文献
46.
Effects of tributyltin compounds on ionic regulation and gill ATPase activity in estuarine fish 总被引:1,自引:0,他引:1
A E Pinkney D A Wright M A Jepson D W Towle 《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1989,92(1):125-129
1. Striped bass (Morone saxatilis) were exposed to 0, 0.10, 0.34, or 1.09 micrograms/l tributyltin (TBT) for 14 days. Gill Mg2+ ATPase and serum Na+, K+, Ca2+ and Mg2+ were not altered. Na+K+ATPase was significantly (P less than 0.05) increased (+48%) at 0.10 microgram/l. 2. In striped bass gill homogenates exposed to TBT in vitro, there was significant inhibition of Na+K+ATPase at 106.0 micrograms/l (17.2%) and Mg2+ATPase at 53.0 and 106.0 micrograms/l (16.0% and 24.3%, respectively). 3. In mummichog (Fundulus heteroclitus) gill homogenates, there was significant inhibition of Na+K+ATPase at 25.3 and 50.5 micrograms/l (10.9% and 16.1%) and Mg2+ATPase at 5.1, 25.3, and 50.5 micrograms/l (26.7%, 32.2%, and 36.2%). 相似文献
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John A. Boezi Lucy F. Lee Robert W. Blakesley Mark Koenig Howard C. Towle 《Journal of virology》1974,14(5):1209-1219
49.
Expression of IL-1 genes in human and bovine chondrocytes: a mechanism for autocrine control of cartilage matrix degradation 总被引:5,自引:0,他引:5
F Ollivierre U Gubler C A Towle C Laurencin B V Treadwell 《Biochemical and biophysical research communications》1986,141(3):904-911
In this report we describe the presence of interleukin-1 activity in medium conditioned by bovine articular cartilage. Preparations partially purified by Sephacryl S200 chromatography (Mr 18000-25000) stimulate murine thymocyte proliferation in the lymphocyte activation factor assay. Furthermore, the factor(s) activate cartilage tissue to secrete a protease which is essential for the activity of purified synovial collagenase. We also demonstrate the presence of mRNA coding for IL-1 alpha and beta in human articular chondrocytes and conclude that the human monocytic and chondrocytic mRNAs are identical. Our results demonstrating cartilage expression of IL-1 genes suggest the possibility of an autocrine mechanism whereby chondrocyte production of matrix degrading proteases is initiated by chondrocyte derived IL-1. 相似文献
50.