Design of the purification process by metal-chelate affinity chromatography of a new vaccine antigen for the control of sea lice
Abstract
The present work aims at designing the purification process of protein MY32/Ls to obtain the active pharmaceutical ingredient (API) against sea lice, marine pathogen that significantly affects the salmon industry in South America and Europe. A compact purification process was designed, based on the analysis of alternatives to establish the steps of rupture, chromatography and renaturation. Due to technical-economic advantages, a chemical rupture process was established using 8 mol/L urea for 1 hour, which was 20 % cheaper than mechanical rupture with glass beads. For washing and elution of the protein in the chromatographic step, pH and imidazole were evaluated. Imidazole was selected for the technical-economic advantages it offered; the costs of the selected variant were 12.33 % lower than washing and elution by pH. In scaling the chromatographic step, an economic variant was assessed with modifications of the urea concentration in washing and elution, lowering the costs of the step 3.4 %, which was moreover attractive for its impact on reducing volumes to be handled in the renaturation step. Tween 80 was selected in the renaturing step, which allowed obtaining the protein in solution. The obtained API induced higher antibody titers in C57Bl/6 mice than the laboratory standard used (three times more on average). The API specifications satisfy the requirements for the formulation of the new vaccine against sea lice.
