Construction of synthetic DNA and its use in large polypeptide synthesis

A DNA composition having a total DNA sequence of at least 900 nt encoding a peptide containing at least one oligopeptide repeating unit, which repeating unit is characterized by containing at least three different amino acids and a total of from 4 to 8 amino acids, there being at least two repeating units or multimers in said peptide and at least two identical amino acids in each repeating unit, said DNA sequence having the following formula:

• K.sub.k (WX.sub.x).sub.i L.sub.1
• wherein:
• K and L are each DNA sequences encoding an amino acid sequence of from about 1 to 100 amino acids, K and L being fewer than about 20 number % of the total amino acids;
• k and l are 0 or 1;
• W is of the formula:
• [(A).sub.n (B).sub.p ].sub.q
• A is the DNA sequence encoding the repeating unit peptide GAGAGS, SGAGAG, VPGVG, or GVGVP, at least two codons coding for said identical amino acid in said repeating units being different, where there will be at least two different A's differing by at least one nucleotide;
• B is a DNA sequence different from A coding for other than the oligopeptide unit coded by the A unit and having from about 3 to 45 nt, where the B units may be the same or different;
• n is an integer in the range of 1 to 100;
• each p is independently 0 or 1;
• and
• q is at least 1;
• X is the same as or different from W and is of the formula:
• [(A.sup.1).sub.n.sup.1 (B.sup.1).sub.p.sup.1 ].sub.q.sup.1
• wherein:
• all of the symbols come within the definitions of their letter counterparts;
• x is 0 or 1;
• i is 1 to 100;
• and
• the total of q, and q.sup.1 is at least 2 and not greater than about 50.