Tibetan Sheep Mammary Gland Lysozyme:Molecular Cloning,Prokaryotic Expression and Its Antibacterial Activity

The full length of LZM cDNA sequence in mammary gland of Tibetan sheep was cloned into pET-32α,generating a recombinant plasmid pET-32α-LZM which was successfully expressed its protein product in Escherichia coli BL21.The agarose diffusion assay showed that recombinant LZM inhibited the growth of Staphylococcus aureus.Sequence comparison and phylogenetic analysis indicated that LZM gene in mammary gland of Tibetan sheep was most similar to goat.Quantitative Real-Time PCR(qRT-PCR) results showed that LZM mRNA had a highest expression level in the mammary gland.In conclusion,it laid a solid foundation for further study.