| abstract |
The present invention relates to a DNA expression cassette comprising the following sequence: 5'-P-SP-LS-PS-*gene*-(T)i-3'wherein P is a promoter sequence, SP is a DNA sequence encoding a signal peptide, LS is a DNA sequence encoding a leader peptide of formula I: GinProIle(Asp/Glu)(Asp/Glu)X1(Glu/Asp)X2AsnZ(Thr/Ser)X3 (SEQ ID NO: 77) (I) wherein X1 is a peptide bond or a codable amino acid; X2 is a peptide bond, a codable amino acid or a sequence of up to 4 codable amino acids which may be the same or different; Z is a codable amino acid except Pro; and X3 is a sequence of from 4 to 30 codable amino acids which may be the same or different; PS is a DNA sequence encoding a processing site; *gene* is a DNA sequence encoding a polypeptide; T is a terminator sequence; and i is 0 or 1. |