Biased mutagenesis in the N-terminal region by degenerate oligonucleotide gene shuffling enhances secretory expression of barley alpha-amylase 2 in yeast.

The crystal structure of A 42P rAMY2 was solved and found to differ marginally from the AMY2 structure, suggesting that the high A42P yield stems from stabilization of the mature and/or intermediate form owing to the introduced proline residue.