Inhibitory effect of icariin on acetylcholinesterase / 药学学报

Acetylcholinesterase (AChE) inhibitors are mainly used in the treatment of Alzheimer's disease (AD). The inhibitory effect of icariin on the activity of AChE was investigated by inhibition kinetics. The binding interaction and binding sites between icariin and AChE were also studied by using fluorimetry and molecular docking, respectively. The results showed that icariin could potently inhibit the activity of AChE, the IC50 value was determined to be 3.50 x 10(-8) mol x L(-1), and the determined IC50 value to tacrine was 0.75 x 10(-8) mol x L(-1). Kinetic analyses showed that icariin is a reversible and mixed type AChE inhibitor. The inhibition constants K1 and K(IS) were determined to be 2.67 x 10(-8) and 4.43 x 10(-8) mol x L(-1), respectively. Icariin binds selectively to the AChE peripheral anionic site via hydrogen bonds and Van der Waals forces.

Primers for detecting gene rearrangement in different regions of immunoglobulin heavy chain genes and their application in diagnosis of paraffin-embedded lymphoma tissues / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze and optimize the gene rearrangement primers of different frame regions (FR) of immunoglobulin heavy chain (IgH) genes by bioinformatic methods and explore the application of these primers in the detection of paraffin-embedded lymphoma tissues.</p><p><b>METHODS</b>Three pairs of primers from IgH FR1, FR2 and FR3 regions (P1c, P2A and P31, respectively) were selected as the B cell gene rearrangement primers after comparison of the gene fragments in 44 IgH variable and 6 joining regions. Using one pair of T cell receptor (TCR) gamma primer as the T cell gene rearrangement primer, 101 histopathologically confirmed lymphoproliferative samples including 80 B cell lymphomas, 14 T cell lymphomas, and 7 reactive proliferative lymph nodes were examined by PCR for gene arrangement. The DNAs from DG75 and Jurkat cell lines were used as the positive controls for B and T cell lymphoma, respectively, with those from reactive proliferative lymph nodes as the negative control.</p><p><b>RESULTS</b>The positivity rates of IgH primers (P1c, P2A and P31) in the 80 B cell lymphomas were 37.5% (30/80), 52.5% (42/80) and 70.0% (56/80), respectively, and only one of the 14 T cell lymphoma cases was positive for the primers, suggesting significant differences in the detection rates of B cell lymphomas by the 3 primers. The detection rate was increased to 83.9% by combining the results by P31 and P2A primers. No positivity was found in the proliferative reaction tissues.</p><p><b>CONCLUSION</b>Primers from IgH FR3 region genes are more sensitive than that from the FR1 and FR2 regions in the detection of gene rearrangement in paraffin-embedded lymphoma tissues. The detection rates can be increased by combining the results with the primers for IgH FR3 with that of FR2.</p>

Recombinant prokaryotic plasmid construction and high expression of FUS1 gene / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct the prokaryotic plasmid of FUS1 gene for efficient FUS1 expression in E.coli strain Rosetta(DE3)2plys.</p><p><b>METHODS</b>The full-length FUS1 gene was amplified by PCR from the total RNA of umbilical mesenchymal stem cells and cloned into pET-32a(+) vector followed by identification with PCR and sequencing. The recombinant plasmid pET-32a(+)-FUS1 was transformed into the E.coli strain Rosetta(DE3)2plys and the target protein expression was induced by IPTG.</p><p><b>RESULTS</b>The plasmid pET-32a(+)-FUS1 was obtained successfully as verified by PCR and sequence analysis. High expression of the fused FUS1 protein was achieved after induction by low-concentration IPTG (25 micromol/L) for 3 h, and the recombinant FUS1 protein accounted for 40% of the total bacterial protein of Rosetta(DE3)2plys.</p><p><b>CONCLUSION</b>The recombinant FUS1 plasmid has been successfully cloned, which allows highly efficient FUS1 expression in Rosetta (DE3)2 plys.</p>