Oligo Synthesis, Gene Synthesis Solution Provider

Overview

Antibody drugs represent a highly promising class of therapies and have witnessed substantial growth with the approval of new drugs for diverse diseases. Recent advancements in antibody discovery technologies have led to the emergence of numerous novel antibody therapeutics. Historically, antibodies were discovered through established in vivo immunization procedures or in vitro antibody library screening methods. However, the escalating costs and relatively high failure rates associated with traditional drug discovery approaches have underscored the pressing need for in-silico methods, particularly structure-guided approaches. The expansion of data repositories, encompassing protein structures, sequences, and NGS, has significantly augmented the availability of extensive data for antibody discovery. The accessibility of such datasets can profoundly impact the streamlining of the antibody discovery process. Tsingke provides a one-stop service platform from gene to antibody expression to meet extensive needs for specific applications.

FAQ

What are the differences between using HEK293 cells and CHO cells for expressing recombinant antibodies in mammalian systems?

Advantages of CHO cells:

They can grow stably in chemically defined, serum-free suspension culture medium.

The genomic information of these cells is well-understood, and they exhibit reasonable safety in response to human pathogenic viruses.

They are capable of expressing post-translational modifications similar to those in humans.

It is easy to obtain genetically modified cells.

Advantages of HEK293 cells:

They have a faster growth rate.

They have a higher cell density and a high transfection efficiency.

The post-translational modifications they express are more similar to the structure of human proteins.

Do the expressed recombinant antibodies have activity?

The advantage of eukaryotic expression systems over prokaryotic systems is that the protein activity is generally better. In theory, most proteins expressed in eukaryotic systems are active. However, the stability of different samples may vary, so the actual experimental results should be used as the basis for determining protein stability.

How can I improve the stability of antibodies?

Optimize elution conditions: Gradually lower the pH during elution to optimize the process.

Timely neutralization: Neutralize the purified sample promptly, and consider neutralizing during the purification process if necessary.

Low-temperature storage: Ensure the samples are prepared and stored at low temperatures during the purification process.

Add protein protectants: Include protectants such as glycerol or Tween to help stabilize the protein.

Dilute high-concentration antibodies: When antibody concentrations are high, dilute them promptly to avoid the risk of aggregation at high concentrations.

How can I increase the yield of recombinant antibodies?

Select a high-expression system: Choose an expression system that is suitable for your target protein.

Prepare endotoxin-free, high-quality plasmids: Ensure plasmid quality by eliminating endotoxins and maintaining high purity.

Ensure good cell condition: Verify that the cells are in a healthy growth state for optimal protein expression.

Expression optimization: If time allows, optimize the expression conditions for higher yield and quality.

Extend expression time: Consider extending the expression time to allow for better protein accumulation.

Increase purification yield: Optimize purification steps to improve the overall yield and purity of the protein.

What is an antibody?

Antibodies (Ab) are globular proteins secreted by effector B cells (effector lymphocyte B cells) and are used by the body to defend against foreign substances (such as viruses, bacteria, and other antigens). Their structure is Y-shaped, and they are found only in the blood of vertebrates and on the surface of B lymphocyte membranes.

Light Chain (L chain):

The light chain consists of approximately 214 amino acid residues and has a molecular weight of about 24 kDa. Each light chain contains two cyclic peptides formed by intrachain disulfide bonds. Light chains can be classified into two types: κ (kappa) and λ (lambda). An antibody molecule contains only one of these two types of light chains. The κ/λ ratio varies across species. For example, in mouse antibodies, the κ:λ ratio is about 20:1, while in normal human antibodies, it is approximately 2:1.

Heavy Chain (H chain):

The heavy chain is composed of approximately 450–550 amino acid residues, with a molecular weight of about 55 kDa or 75 kDa, making the heavy chain roughly twice the size of the light chain. Based on the type of heavy chain, there are five classes: μ (mu), γ (gamma), α (alpha), δ (delta), and ε (epsilon). Different heavy chains combine with light chains (either κ or λ) to form complete immunoglobulin (Ig) molecules, which are classified as IgM, IgG, IgA, IgD, and IgE.

Antibody Service