Gene design of signal sequence for the effective secretion of recombinant protein using insect cell

In order to increase the proteinic secretion quantity of production in insect cell, the chicken lysozyme signal peptide (CLSP) was altered, and the effect of mutations on secretion of human lysozyme (HLY), the bovine interferon beta-3, and the equine interferon alpha-1 were studied. A hybrid gene composed of CLSP gene and HLY gene was used for the production of recombinant HLY in insect cell (BmN4) using vacuole virus expression system. In contrast with the Leu rich signal peptide in previous reports, Val rich type, or Ile rich type decreased the secretion of HLY, and Phe rich type prevented it completely, in spite of the increase of hydrophobicity in the central core region of each signal peptide. Besides the hydrophobicity, the tertiary structure in this region also might influence the secretion of HLY in insect cells. Then, Leu-rich signal peptide was used for the secretion of the bovine interferon beta-3, or the equine interferon alpha-1, resulted in the remarkable increase of the amount of the secretion in insect cells.