Antibody fragments have promising applications in pharmaceuticals due to their specific binding abilities and distinct mode of action from full-size antibodies. The challenge lies in developing efficient production methods and protein engineering strategies for generating them.

Kuwahara et al. discussed antibody fragment formats and various methods of engineering them. They covered both the upstream process, where antibodies are heterologously produced, and the downstream process, where antibodies are separated from contaminants.

“The research and development of antibody fragments are now gathering attention,” said author Atsushi Kuwahara. “Many antibody fragments have been approved in the last decade. We think this trend will continue, and we hope our work further accelerates the development of antibody fragments in the pharmaceutical field by shortening the process construction on production research.”

Of the methods the group surveyed, complementarity-determining region (CDR) grafting shows promise for both upstream and downstream processes, and domain arrangement and mutagenesis stand out as engineering strategies for upstream and downstream processes, respectively.

The team also highlighted the use of solubility tags for high-level soluble expression and affinity tags for purification as key drivers for future development. Recent work in this area offers a wide range of possibilities for the efficient and secure production of antibody fragments.

The researchers caution, however, that fusion tags might negatively impact molecular folding, function, and final yield. Researchers should carefully design antibody fragments considering these points.

Kuwahara hopes to inspire further work balancing aspects like function, pharmacokinetics, productivity, and stability.

Source: “Protein engineering of antibody fragments for pharmaceutical production,” by Atsushi Kuwahara, Ryutaro Asano, and Kazunori Ikebukuro, Applied Physics Reviews (2023). The article can be accessed at