Expression, activation and processing of a novel plant milk-clotting aspartic protease in Pichia pastoris.

•Cloning and expression of a plant aspartic protease (preprogaline B) in Pichia pastoris.•Obtention of the preprogaline B either active or inactive form by change of pH medium.•Description of activation process in the culture medium.•Preprogaline B has milk clotting activity.•Preprogaline B shows the same hydrolysis pattern on bovine κ-casein than chymosin, but different on α- and β-casein.