Abstract: There exists two groups of purple acid phosphatases(PAPs). Mammalian PAPs, which are monomers with molecular weight in the range of 33000-40000. Plant PAPs, which are dimers or tetramers containing identical subunits of about 55000. Recently the gene of low molecular weight PAPs(smPAPs) was found in plant. They are significantly similar to mammalian PAPs' but quite different from plant PAPs'. In order to understand the exact function of the protein and its distribution in plant, we cloned the sweet potato smPAPgene in pGEX-2T vector and expressed the fusion protein in E. coli. The expressed fusion protein was used to generate polyclonal antibodies. The antibodies demonstrated a good reactivity towards the smPAPexpressed in baculovirus and PAPs partially purified from sweet potato juice. Therefore, the antibodies make it possible to purify and characterize the smPAP.

Key words: Purple acid phosphatase, Fusion protein, Polyclonal antibodies