A protein processing and expression platform for efficient production of mature, high-purity therapeutic proteins

Background

The production of therapeutic proteins, such as insulin and its analogs, is a cornerstone of modern biotechnology and pharmaceutical manufacturing. These proteins are typically synthesized as larger, inactive precursor molecules (prohormones) that require precise enzymatic processing to yield their mature, biologically active forms. Efficient and accurate conversion of these precursors is essential for ensuring the safety, efficacy, and cost-effectiveness of protein-based drugs. As the demand for recombinant protein therapeutics continues to rise, particularly for chronic conditions like diabetes, there is a growing need for manufacturing processes that maximize yield, minimize impurities, and are adaptable to a variety of protein targets, including engineered analogs with altered amino acid sequences.

Current approaches to processing precursor proteins, especially in the context of insulin and its analogs, predominantly rely on trypsin, a protease with broad specificity for basic amino acids. While trypsin is effective for some substrates, its lack of selectivity often leads to the generation of undesirable byproducts, particularly when processing engineered analogs such as insulin glargine that contain additional basic residues. These byproducts complicate downstream purification, reduce overall yield, and increase production costs. Attempts to mitigate these issues, such as chemical blocking of reactive residues, have not fully resolved the problem and can introduce additional complexity. Consequently, there is a significant need for more selective and efficient processing methods that can reliably produce high-purity therapeutic proteins without the drawbacks associated with traditional enzymatic approaches.

Technology

This technology provides an advanced method for producing mature, biologically active proteins—such as insulin and its analogs—by leveraging the highly specific KEX2 protease from yeast. Unlike traditional approaches that rely on trypsin, which often generates unwanted byproducts due to its broad specificity, this method utilizes engineered precursor proteins containing KEX2 cleavage sites. These precursor proteins can be further enhanced with De novo Expression Enhancer Protein (DEEP) tags, which are specially designed α-helical polypeptides that improve expression, folding, and purification. The process involves expressing the DEEP-tagged precursor in a suitable host (such as E. coli), purifying the fusion protein, and then cleaving it with KEX2 protease to yield the mature protein with high efficiency and minimal byproducts. The system is supported by a suite of molecular tools, including optimized polynucleotides, expression vectors, and purification kits, making it adaptable for both in vitro and in vivo applications.

What differentiates this technology is its combination of high specificity and modular design, which collectively address longstanding challenges in protein biomanufacturing. KEX2 protease’s precise recognition of dibasic amino acid sequences allows for clean, efficient conversion of precursor proteins without the extensive byproduct formation typical of trypsin-based methods—particularly important for engineered analogs like insulin glargine. The inclusion of DEEP tags not only boosts expression and folding in diverse host systems but also streamlines purification through affinity techniques, thanks to engineered histidine residues. This integrated approach reduces the need for complex downstream processing, increases overall yield, and enhances product purity. As a result, the technology offers a scalable, versatile platform for producing a wide range of therapeutic proteins, setting a new standard for efficiency and quality in biomanufacturing.

Benefits

• High specificity of KEX2 protease reduces byproduct formation, enhancing purity of mature proteins.
• Improved yield of mature, biologically active proteins compared to traditional trypsin-based methods.
• DEEP fusion tags enhance expression, folding, and simplify purification of precursor proteins.
• Applicable to a wide range of precursor proteins with dibasic cleavage sites, including therapeutic hormones like insulin analogs.
• Compatible with both in vitro and in vivo production systems, supporting scalable biomanufacturing.
• Facilitates streamlined downstream processing, reducing production costs and complexity.

Applications

• Insulin analog biomanufacturing
• Therapeutic peptide production
• Recombinant hormone processing
• Affinity-tagged protein purification

Additional info

This technology describes a method for producing mature proteins by contacting a precursor protein, containing a KEX2 cleavage site, with KEX2 protease. This highly specific enzymatic process efficiently converts the precursor into its active form with minimal byproducts. Precursors can be engineered as fusion proteins with α-helical DEEP tags to enhance expression, folding, and purification, yielding high-purity therapeutic proteins like insulin analogs.