Avian immunoglobulin Y (IgY), found in egg yolk, has potential to be used as a biopharmaceutical. Contrarily to its analogous mammalian immunoglobulin G (IgG), IgY presents high immunogenicity and binding avidity, and the ability to be recovered by a non-invasive method [1-3]. The amount of IgY obtained from an egg is equal to that from 200-300 mL of mammalians blood, being possible for a chicken produce 17-35 g of total IgY [1,4]. By being a polyclonal antibody, IgY antibodies recognize several epitopes on an antigen and have various applications, such as in the treatment of several diseases [1,2]. However, by being proteins present in a complex media, the use of IgY as a biopharmaceutical is restricted by its recovery at high yields and high purity, along with their preservation [5]. This work aimed to improve the stability of IgY during storage, so that it can be used as a biopharmaceutical. IgY antibodies were isolated from the yolk of commercial chicken eggs and purified by two precipitation steps. Their stability was assessed by Circular Dichroism Spectroscopy (CD) under 1-3 weeks of storage at -20 ºC. Trehalose and xylitol at several concentrations were investigated as stabilizers agents. The IgY purity degree, concentration and the percentage of aggregates formed during storage were determined by Size Exclusion- High Performance Liquid Chromatography (SEC-HPLC), whereas the protein profile was revealed by dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Both stabilizers allowed promising results and are potential stabilizing agents for IgY. A decrease in the percentage of aggregates was verified in IgY formulations with trehalose and xylitol in all storage conditions. It was confirmed the presence of β-sheets in the IgY secondary structure, and no substantial evidence of its secondary structure degradation occurred over storage with the stabilizing agents.

published