Abstract

This work presents the development of an expert system for selecting the best sequence of operations for the downstream processing of proteins. The core of the discussion is how the rationale for the selection of a sequence of processes for purification was developed. It consists of a system that compares extensive data on the product to be purified and on the main contaminant proteins found in the expression system to be used (e.g. E. coli). Definitions of parameters that translate (i) the rules employed in separations and (ii) the selection between high-resolution purification operations (chromatography) using the databases of properties of proteins in a rational quantitative manner to guide the selection are described. after each separation step, there is a reduction in the amount of contaminant proteins. The amount of each 'contaminant' eliminated is determined using an algorithm developed for this purpose, based on simplified interpretations of chromatograms, that indicates the new concentrations after each step. The number of steps must be sufficient to achieve a defined level of purity. The comparison of the concentration of the product after the separation with the defined level of purity indicates whether an additional step is necessary.