Institute for Research Management, Oita University, 700 Dannoharu, Oita-shi, Oita, 870-1192, Japan.
Research Center for GLOBAL/LOCAL Infectious Diseases, Oita University, 700 Dannoharu, Oita-shi, Oita, 870-1192, Japan.
Sci Rep. 2024 May 28;14(1):12184. doi: 10.1038/s41598-024-63116-6.
Catalytic antibodies possess a dual function that enables both antigen recognition and degradation. However, their time-consuming preparation is a significant drawback. This study developed a new method for quickly converting mice monoclonal antibodies into catalytic antibodies using site-directed mutagenesis. Three mice type monoclonal antibodies targeting hemagglutinin molecule of influenza A virus could be transformed into the catalytic antibodies by deleting Pro95 in CDR-3 of the light chain. No catalytic activity was observed for monoclonal antibodies and light chains. In contrast, the Pro95-deleted light chains exhibited a catalytic activity to cleave the antigenic peptide including the portion of conserved region of hemagglutinin molecule. The affinity of the Pro95-deleted light chains to the antigen increased approximately 100-fold compared to the wild-type light chains. In the mutants, three residues (Asp1, Ser92, and His93) come closer to the appropriate position to create the catalytic site and contributing to the enhancement of both catalytic function and immunoreactivity. Notably, the Pro95-deleted catalytic light chains could suppress influenza virus infection in vitro assay, whereas the parent antibody and the light chain did not. This strategy offers a rapid and efficient way to create catalytic antibodies from existing antibodies, accelerating the development for various applications in diagnostic and therapeutic applications.
催化抗体具有双重功能，既能识别抗原又能降解抗原。然而，其制备过程耗时较长，这是一个显著的缺点。本研究通过定点突变开发了一种将小鼠单克隆抗体快速转化为催化抗体的新方法。通过删除流感 A 病毒血凝素分子的 CDR-3 中的 Pro95，可将三种针对血凝素分子的小鼠单克隆抗体转化为催化抗体。单克隆抗体和轻链没有催化活性。相比之下，Pro95 缺失的轻链对包括血凝素分子保守区部分的抗原肽具有催化活性。与野生型轻链相比，Pro95 缺失的轻链对抗原的亲和力增加了约 100 倍。在突变体中，三个残基（Asp1、Ser92 和 His93）更接近合适的位置以形成催化位点，并有助于增强催化功能和免疫反应性。值得注意的是，Pro95 缺失的催化轻链可抑制体外流感病毒感染，而亲本抗体和轻链则不能。该策略为从现有抗体中快速有效地产生催化抗体提供了一种方法，加速了诊断和治疗应用等各个领域的发展。
