Engineering Homogeneous Photoactive Antibody Fragments.

Area of Science:

• Biochemistry
• Molecular Biology
• Immunology

Background:

• Noncanonical amino acids (ncAAs) enable protein property modulation.
• Site-specific incorporation of ncAAs allows precise engineering of protein function.

Purpose of the Study:

• To engineer photoactive antibody fragments that bind antigens upon 365 nm light irradiation.
• To develop a method for assessing the binding affinity of these photoactive antibodies to cancer cells.

Main Methods:

• Identification of key tyrosine residues in antibody fragments crucial for antigen binding.
• Site-specific replacement of tyrosine with photocaged tyrosine (pcY).
• Expression of pcY-containing antibody fragments in E. coli.
• Measurement of binding affinity to cell-surface expressed antigens on live cancer cells.

Main Results:

• Successful engineering of antibody fragments exhibiting light-dependent antigen binding.
• Demonstration of a cost-effective method for evaluating photoactivatable antibody performance.
• Validation of the approach using live cancer cells.

Conclusions:

• This procedure enables the creation of photoactivatable antibody fragments with controlled antigen binding.
• The developed method provides a biologically relevant platform for assessing photoactive antibody efficacy.
• This technology holds potential for applications in targeted therapies and diagnostics.