Influence of ATP-binding cassette transporter A1 protein in eukaryocyte and its expression on arsenic resistance / 中国地方病学杂志

Objective To examine the expression of ATP-binding cassette transporter A1(ABCA1)in eukaryotie cells and the effect of arsenic resistance after the transfection of eukaryotic expression vector containing ABCA1 gene.Methods HeLa cells were transfected with the recombinant plasmid by lipofectaonmine 2000 (recombinant plasmid group),empty plasmid and untransfected HeLa cell as the control group.The level of the mRNA was examined by real-time PCR,and the expression of ABCA1 protein wag examined by Western blot,the change of cell survival rate was examined by methyl thiazolyl tetrazolium(MTT)after exposure in a series of arsenic [0(contro1),4,8,16,32,64,128 μmol/L]for 48 hours.Results Expression level of ABCA1 mRNA in recombinant plasmid,empty plasmid and untransfeeted groups was(2.09±0.08)×10-4,(0.09±0.02)×10-4,(0.08±0.02)×10-4,there was a significant difference between the groups(F=1499.23,P<0.01).The level of ABCA1 mRNA in recombinant plasmid group was higher than empty plasmid and untransfected group(all P<0.01).Western blot showed that specific protein straps existed at 254×103 in all the three groups,with a similar size to the ABCA1 protein.The amount of the recombinant plasmid group was higher than the other two groups.MTT shows that arsenic concentration at 4,8,16,32,64,128 μmol/L,the survival rates of recombinant plasmid group was(94.8±0.9)%,(86.5 ± 2.6)%, (77.8 ± 2.0)%, (56.0 ± 2.0)%, (23.8 ± 1.7)%, (18.6 ± 0.6)%, higher than that of empty plasmid group[ (85.3 ± 1.1)%, (78.7 ± 0.6)%, (67.8 ± 2.4)%, (43.2 ± 1.5)%, (14.5 ± 1.3)%, (8.0 ± 0.4)%], the difference of survival rate had a statistical signifieance(t = 18.985,6.689,5.922,9.504,9.481,32.634, all P < 0.01). Conclusions ABCA1 protein is over expressed in HeLa cells after transfect ABCA1 gene. ABCA1 protein increases resistance of arsenic in HeLa cells.

Expressing, Purification and Identification of Neuritin Gene in the E. coli / 中国生物工程杂志

Neuritin is a new neurotrophic factor found recently. In order to identify the function of Neuritin clearly, the coding sequence of human neuritin was amplified by PCR from neuritin cDNA , this fragment digested by NocI and NotI was inserted into pET32a by T4 ligase and transformed into E. coli BL21 then the recombinant plasmid named pET32a-neuritin was constructed successfully . Neuritin was expressed distinctly after inducing by EPTG. The product was identified as neuritin by SDS-PAGE and Western blot analysis . The expression production was purified on Ni2+-NTA column.