Chromatography Resins for Insulin Purification

Insulin is a 51-amino acid peptide with a molecular weight of 5.8 kDa, which is important for the regulation of carbohydrate metabolism. Insulin is synthesized in the beta cells of the islets of Langerhans of the pancreas. Lack of insulin leads to severe hyperglycemia, which in turn leads to a life-threatening diabetic metabolic disease. The physiological regulator of insulin biosynthesis is the blood glucose concentration. An increase in the concentration of blood glucose stimulates insulin biosynthesis. Insulin is composed of two peptide chains linked by two disulfide bonds. The two peptide chains are A-chain with 21 amino acids and B-chain with 30 amino acids. The third disulfide bond in the A chain is important for stabilizing the spatial structure of insulin. Many genetically modified human insulins with short or long half-lives are designed and developed for the treatment of diabetes.

Resins for Insulin Purification

The production of insulin by different expression systems additionally generates "insulin-like" impurities that are very similar to insulin itself. These impurities can be difficult to eliminate, so multiple orthogonal chromatography steps are often required in the purification of insulin. Amerigo Scientific offers reliable ion-exchange media and reversed phase media for the orthogonal chromatography purification of insulin.

In the capture step, fast flow ion-exchange chromatography media with large binding capacity, good alkali resistance, and long service life are used to capture and concentrate large amounts of fermentation products. UniGel®-80SP is a highly crosslinked polymethacrylate microspheres with a uniform particle size of 80µm and an open pore structure, which can be used to efficiently capture insulin at low back pressure and very high flow rate.

The intermediate purification step requires high-resolution chromatography media to remove many impurities. Both ion-exchange chromatography media and reversed-phase media can be applied for this step. Polystyrene substrates such as NanoSP-15L or NanoSP-30L media are widely used in this step due to their advantages of high resolution and long life of the packed column.

For the polishing step, silica-based reversed phase media such as Uni® InsulinC8 Type A and Uni® InsulinC8 Type B are preferred due to their high resolution and high column efficiency, which is very effective in removing insulin-like impurities. Uni® Insulin C8 media are designed for the isolation and purification of insulin. They are made of a monodisperse UniSil® Ultra Plus matrix using the proprietary end-capping and bonding technologies, and therefore have high mechanical strength, good resolution, high recovery, and excellent alkaline resistance (pH 2-12).

Purification of Recombinant Human Insulin