Recombinant Insulin-like Growth Factor-1 (rIGF-1) Engineering Service

Recombinant Insulin-like Growth Factor-1 (rIGF-1) is a critical therapeutic protein used in treating growth disorders and is being researched for various metabolic and neurodegenerative diseases. Its industrial production is challenging: prokaryotic expression systems (like E. coli ) tend to form inclusion bodies , requiring complex and costly refolding, while eukaryotic expression in mammalian cells incurs a high cost due to complex media and slow growth rates.

CD Biosynsis offers a dedicated expression system optimization service focusing on the methylotrophic yeast Pichia pastoris (now Komagataella phaffii ). Our core strategy involves the optimization of the secretion expression system in Pichia pastoris , utilizing powerful promoters and enhanced signal peptides to maximize the secretion of soluble, correctly folded rIGF-1. This is complemented by the improvement of protein refolding processes for any protein that still aggregates. This integrated approach aims to deliver a high-yield, correctly folded, and cost-efficient rIGF-1 manufacturing route.

Pain Points

The production of functional rIGF-1 is restricted by these expression and quality challenges:

• Inclusion Body Formation: rIGF-1 contains three disulfide bonds ; when expressed at high levels in E. coli (prokaryotic), it often precipitates into inactive inclusion bodies, necessitating a low-yield refolding step.
• High Eukaryotic Cost: While mammalian systems produce correctly folded protein, their use involves expensive, serum-containing media, low cell density, and challenging scale-up , leading to high production costs.
• Inefficient Secretion: Even in yeast hosts like Pichia , the native secretion pathway may be saturated or inefficiently processed (e.g., incomplete cleavage of the signal peptide), limiting final soluble yield.
• Glycosylation Variability: Although rIGF-1 is naturally non-glycosylated, misdirected glycosylation in yeast can occur, which may affect biological activity or immunogenicity .

A successful solution must combine the cost-effectiveness of microbial hosts with the folding capacity of eukaryotes.

Solutions

CD Biosynsis utilizes advanced Pichia pastoris engineering and biochemical process optimization:

Optimization of the Secretion Expression System in Pichia pastoris

           

We engineer the expression cassette using strong, often inducible promoters (e.g., AOX1) and optimized signal peptides (e.g., $\alpha$-factor) to maximize protein export.

Improvement of Protein Refolding Processes

For aggregated rIGF-1 produced, we develop optimized chemical refolding protocols involving specific redox systems, additives (e.g., L-Arginine), and precise temperature control to maximize active yield.

Chaperone Co-expression for Folding

We co-express genes encoding folding catalysts (e.g., PDI, Kar2) and chaperones in Pichia to enhance the rate and efficiency of disulfide bond formation and correct folding.

Glycosylation Site Mutation

If necessary, we perform targeted gene editing to remove or mutate cryptic N-glycosylation sites within the rIGF-1 sequence to prevent unwanted post-translational modification.

This systematic approach is focused on leveraging Pichia 's high-density fermentation capacity while ensuring correct protein folding and solubility.

Advantages

Our rIGF-1 engineering service is dedicated to pursuing the following production goals:

High Soluble Yield

Optimized Pichia secretion aims to maximize the titer of correctly folded, active rIGF-1 in the culture supernatant.

Simplified Purification

Secretion into the medium dramatically simplifies downstream purification compared to intracellular expression, as cell lysis is avoided.

Correct Disulfide Bond Formation

The eukaryotic environment of Pichia and chaperone co-expression facilitates the correct formation of the three required disulfide bonds for activity.

Cost Efficiency

Pichia high-density fermentation allows for reduced fermentation and media costs compared to slow-growing mammalian systems. [Image of Cost Reduction Icon]

High Fermentation Density

Pichia pastoris is capable of achieving very high cell densities in simple defined media, leading to a high volumetric productivity.

We provide a specialized platform aimed at maximizing the quality and cost-effectiveness of rIGF-1 biomanufacturing.

Process

Our rIGF-1 strain engineering service follows a rigorous, multi-stage research workflow:

• Vector Construction and Optimization: Clone the rIGF-1 gene into a Pichia vector with an optimized promoter (AOX1 or constitutive) and $\alpha$-factor signal sequence .
• Secretion Pathway Engineering: Overexpress co-factors and chaperones involved in the disulfide bond formation and ER export pathways to boost secretion efficiency.
• Strain Integration and Screening: Integrate the expression cassette into the Pichia genome and perform high-throughput screening for high-titer secretory clones .
• Refolding Protocol Development: If needed, systematically test and optimize the refolding buffer components (urea/GdnHCl, redox couple, pH) to maximize the recovery of active rIGF-1.
• Bioreactor Performance Validation: Test the final engineered strain in high-density, fed-batch fermentation to assess volumetric productivity and product quality (purity, activity) .
• Result Report Output: Compile a detailed Experimental Report including vector maps, host modification details, refolding protocols, and final titer/activity assessment , supporting scale-up and regulatory work.

Technical communication is maintained throughout the process, focusing on timely feedback regarding secretion titer and protein folding efficiency.

Explore the potential for a cost-efficient, high-quality rIGF-1 supply. CD Biosynsis provides customized expression system solutions:

• Detailed Titer and Bioactivity Analysis Report , illustrating the final yield and functionality of the secreted protein.
• Consultation on fermentation and purification strategies optimized for the Pichia secreted product.
• Experimental reports include complete raw data on solubility, disulfide bond formation efficiency, and scale-up parameters , essential for biomanufacturing assessment.