Methods for producing and purifying recombinant alpha-L-iduronidase

A method of purifying human recombinant α-L-iduronidase, or a biologically active fragment or mutein thereof, comprising the steps of

• a) obtaining culture medium from a culture of Chinese Hamster Ovary (CHO) cells that have been transformed with a nucleic acid that encodes said human recombinant α-L-iduronidase;
• b) adjusting the pH of the culture medium to an acidic pH;
• c) subjecting said pH-adjusted medium to ultrafiltration;
• d) subjecting the filtered medium produced by step (c) to a first dye-affinity chromatography purification step;
• e) subjecting the eluant from step (d) to a first metal-ion chelate chromatography step;
• f) subjecting the eluant from step (e) to a hydrophobic interaction chromatography (HIC) step;
• and
• g) concentrating and diafiltering the eluant from step (f), to yield a purified preparation of purified human recombinant α-L-iduronidase which has a greater than 99% purity as determined by quantity of contaminating CHO protein per mg of total protein in said preparation.