Abstract: A synthetic antifreeze peptide and a synthetic gene coding for the antifreeze peptide have been produced. The antifreeze peptide has a greater number of repeating amino acid sequences than is present in the native antifreeze peptides from winter flounder upon which the synthetic antifreeze peptide was modeled. Each repeating amino acid sequence has two polar amino acid residues which are spaced a controlled distance apart so that the antifreeze peptide may inhibit ice formation. The synthetic gene has been expressed in E. coli. A synthetic insert fragment has been prepared which can be readily inserted into the synthetic gene to alter the number of repeating units and/or amino acid composition in the antifreeze peptide produced.