FAQs on Recombinant Protein Expression

Q1: What types of expression systems and protein services does Camed offer?

A1: We currently offer E. coli, mammalian, yeast, and baculovirus (insect) expression systems. We provide a wide range of production and purification services, including tag removal, lyophilization, endotoxin removal, fermentation, N-terminal sequencing, and QC testing. Our gene synthesis service also allows us to synthesize and subclone your genes, preparing them for protein production.

Q2: Under what circumstances should the baculovirus (insect) expression system be chosen?

A2: Baculovirus (insect) expression is an ideal method for producing mature, folded, and processed recombinant proteins. Unlike E. coli, insect cells are capable of incorporating post-translational modifications, and they are particularly well-suited for expressing secreted proteins.

Q3: Under what circumstances should a mammalian expression system be chosen?

A3: Proteins produced in mammalian cells have the advantage of containing all post-translational modifications of the expressed protein (e.g., proper folding, glycosylation, phosphorylation, etc.). However, expression levels in mammalian systems are often lower, resulting in higher costs, and it is more difficult to achieve high-volume protein expression (>10 mg).

Q4: What do I need to provide? Can I use a plasmid I’ve constructed myself?

A4: We offer codon optimization and gene synthesis services, so you only need to provide your gene/protein sequence or an NCBI entry. Alternatively, we can use a plasmid you’ve constructed. We also require you to fill out our protein order form so we can understand your specific requirements.

Q5: Will you purify the protein using an affinity tag? What if I need the tag removed?

A5: Yes, we will use affinity tags (such as His or GST) to purify your protein. For proteins that are difficult to express, we can also try other tags (including SUMO or thioredoxin) to increase solubility and expression. If needed, we can cleave the tag and deliver the untagged protein as the final product.

Q6: Are there any restrictions on the types of proteins that can be produced?

A6: Our experienced protein team will make every effort to purify virtually any protein. However, for optimal results, we recommend that the target protein have a molecular weight <100 kDa and avoid having too many transmembrane domains. We also recommend removing any signal peptides attached to the N-terminus of the protein, as these peptides can inhibit protein expression in the recombinant system. <>

Q7: Can you produce large quantities (milligram to gram scale) of protein?

A7: Yes, using the E. coli expression system, we are capable of producing large quantities of protein in a single batch (up to the gram scale). For these large-scale projects, we typically begin with small-scale protein expression and purification trials; if the results meet the client’s requirements, we can proceed with scale-up experiments. Depending on customer requirements and protein expression conditions, KMD Bioscience’s laboratory can produce proteins in the milligram to gram range for use by research and industrial clients.

    KMD Bioscience specializes in providing comprehensive recombinant protein expression services and related upstream and downstream services, aimed at meeting the demand for high-quality recombinant proteins in scientific research and the biopharmaceutical industry. Our services include gene synthesis, vector construction, host system selection (including bacteria, yeast, insect cells, and mammalian cells), expression optimization, protein expression, purification, and subsequent protein characterization. By leveraging cutting-edge technologies and extensive experience, KMD Bioscience is able to provide clients with one-stop solutions from concept to finished product, ensuring that the recombinant proteins produced are of high purity, high activity, and high stability. Our team has a deep understanding of the complexities involved in recombinant protein production and therefore offers customized services to meet specific project requirements. From project inception to completion, KMD Bioscience is committed to working closely with clients to ensure that each project progresses efficiently and ultimately meets client expectations. Whether for drug development, structural biology research, or other biotechnology applications, KMD Bioscience is a trusted partner, providing professional services and support to advance scientific research and the development of innovative drugs.