Recombinant A17 Lys human insulin: purification and characterization.

Recombinant A17 Lys human insulin precursor expressed in yeast cells was isolated from the culture medium. After purification, the precursor was converted into A17 Lys human insulin. A17 Lys human insulin can be crystallized but has much lower receptor-binding and biological activities than porcine or human insulin where A17 is Glu. It is proposed that the A17 Glu residue may be involved in the receptor-binding or the active site of human insulin.