Synthesis and cloning of the human lysozyme gene

The human lysozyme is an enzyme with potential importance in clinical and industrial application. Owing to the limitation of its natural resource, we are making an attempt to produce the enzyme with the aid of recombinant DNA technology. Twenty-four segments with length ranging from 26 to 38 nucleotides were chemically synthesized by solid phase. The oligonucleotides were joined to form DNA duplexes by two different ligation methods. The entire gene covers a start signal ATG and a BamHI restriction site at its 5' end, and two stop signals TAA TGA and a SphI restriction site at its 3' end, besides the structural gene of human lysozyme. The synthetic gene was cloned into vector M13. The positive colonies were confirmed by dot-blot hybridization and analysis by restriction enzymes. The DNA sequence of the cloned enzyme gene was proved to be correct by M13 dideoxynucleotide chain termination method. The study on gene expression is under way.