ABSTRACT
Abstract: Our previous work revealed berberine can significantly enhance the susceptibility of fluconazole against fluconazole-resistant Candida albicans, which suggested that berberine has synergistic antifungal activity with fluconazole. Preliminary SAR of berberine needs to be studied for the possibility of investigating its target and SAR, improving its drug-likeness, and exploring new scaffold. In this work, 13-substitutited benzyl berberine derivatives and N-benzyl isoquinoline analogues were synthesized and characterized by 1H NMR and MS. Their synergetic activity with fluconazole against fluconazole-resistant Candida albicans was evaluated in vitro. The 13-substitutited benzyl berberine derivatives 1a-1e exhibited comparable activity to berberine, which suggested that the introduction of functional groups to C-13 can maintain its activity. The N-benzyl isoquinolines, which were designed as analogues of berberine with its D ring opened, exhibited lower activity than berberine. However, compound 2b, 2c, and 4b showed moderate activity, which indicated that berberine may be deconstructed to new scaffold with synergistic antifungal activity with fluconazole. The results of our research may be helpful to the SAR studies on its other biological activities.
ABSTRACT
Yeast Elongation protein 3 (yElp3), the catalytic subunit of the multi-subunit histone acetyltransferase elongator complex, is involved in histone acetylation and transcription, exocytosis and tRNA modification. To study the complex function of yElp3 in yeast, we amplified the yElp3 gene fragment encoding 73aa in the N-terminal from plasmid pYES2-yElp3, and then cloned it into pMXB10 to construct the recombinant plasmid pMXB10-yElp3-219. We expressed the fusion protein in E. coli BL21 (DE3), then purified it by chin affinity column, and finally obtained the soluble purified protein (8.0 kD), which was used to immune the rabbits for acquiring antiserum. ELISA and Western blotting indicated that the polyclonal antibody was of high titration and specificity. Chromatin immunoprecipitation (ChIP) assay with this antibody suggested that yhElp3 exerted the transcriptional regulatory function directly through its presence on the SSA3 gene; this might be the reason that it can rescue the delay activation of SSA3 in elp3delta cells.
Subject(s)
Amino Acid Sequence , Antibodies , Allergy and Immunology , Escherichia coli , Genetics , Metabolism , Gene Expression Regulation, Fungal , Histone Acetyltransferases , Genetics , Allergy and Immunology , Molecular Sequence Data , Recombinant Proteins , Genetics , Allergy and Immunology , Saccharomyces cerevisiae Proteins , Genetics , Allergy and ImmunologyABSTRACT
Objective:To examine influences of attention on the conflict monitoring system. Methods:Thirty normal adults participated in the matching-to-sample task. They were divided into two subgroups. One subgroup was required to attend to the color while ignoring the value attribute of a number pair. The other subgroup was required to attend to the value while ignoring the color attribute of a number pair. Subjects were asked to press one of the two buttons according to whether the two digits were identical in the attended attribute and event-related potentials were recorded on their scalps. Results: A N270 component of event-related potential was recorded to the conflicting stimulus pairs but not to the matching pairs. The amplitude of N270 increased and its duration prolonged under attended condition. However, its onset latency showed no significant changes. Conclusion: The conflict monitoring process is automatically initiated and then regulated and enhanced by the attention control system.