[The expression and purification of TRPM2 protein in E.coli and preparation of its polyclonal antibody]

To purify the prokaryotically expressed GST-TRPM2N fusion protein and prepare specific polyclonal antibody against human transient receptor potential melastatin 2(TRPM2) protein.

The DNA fragment encoding evolutionarily conserved N-terminus (1-334 amino acids) of TRPM2 was amplified by PCR. The amplicon was then subcloned into prokaryotic expression plasmid pGEX-4T-3 and the recombinant plasmid was transformed into BL21 (DE3) cells. The expression of GST-TRPM2N fusion protein with a molecular weight about 70 000 Da was induced with 1 mmol/L IPTG and purified by GST affinity chromatography. The purified protein was mixed with complete Freund's adjuvant and used to immunize the New Zealand white rabbits with classical 4-injection protocol to generate specific anti-TRPM2 polyclonal antibody. The specificity and titer of the anti-TRPM2 antibody was analyzed by Western blotting.

The cDNA fragment encoding N-terminus of human TRPM2 was amplified by PCR and directionally subcloned into pGEX-4T3 plasmid. Under the induction of IPTG, we observed the expression of GST-TRPM2N fusion protein. Polyclonal antibody against human TRPM2 protein was successfully prepared in the rabbits immunized with the purified GST-TRPM2N fusion protein. And the preliminary analysis showed that the anti-TRPM2 antibody could specifically identify transiently expressed TRPM2-EE in HEK293 cells.

The specific polyclonal antibody against human TRPM2 protein has been successfully prepared, which facilitates our future research on the function of TRPM2 channel.