The affinity of antibody is a vital parameter that regulates antibody biological function and efficacy. Because of the in vivo affinity ceiling, the affinity of antibody from hybridomas often falls short of the level of effective clinical use and thus improving antibody affinity is often required. Affinity maturation and optimization of a pre-existing antibody can preserve the epitope specificity and its functional activity. Affinity maturation and optimization can also boost the antibody’s potency to the desired level.

With extensive experience and full-length IgG pichia display system, Genekine is able to quickly design focused libraries for the antibody to be optimized, and simultaneously screen for antibodies with higher affinity and higher level of expression. Our system can routinely yield affinity improvement of 5-100 times or greater compared to the parental antibodies.

1. 3-D structural modeling;

2. Construction and display of the mutated full-length IgG library;

3. FACS sorting to screen for IgG with high binding affinity and expression level;

4. Selected IgG binding affinity characterization.

Based on full-length IgG pichia display system, we can systematically analyze each mutation in six CDR region and its effect on binding affinity. Saturation mutations are performed on amino acids in all of the six CDR regions of the light and heavy chains. Each amino acid is mutated into the other 19 amino acids with the same distribution. This IgG site-saturation mutagenesis library is displayed on glycoengineered pichia pastoris and sorted by FACS to identify mutation hot spots. Then based on the hot spots, we will construct a combinatorial mutation library to find the best mutation combinations with desired affinity. This method can improve the screening efficiency and increase the probability to identify high affinity sequences.