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Biological features of human catalytic antibody light chains showing anti‐cancer activity
Author(s) -
Uda Taizo,
Hifumi Emi
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.611.1
Subject(s) - clone (java method) , immunoglobulin light chain , microbiology and biotechnology , catalytic triad , complementary dna , antibody , biology , cytotoxicity , mutant , biochemistry , chemistry , gene , peptide sequence , genetics , in vitro
The authors have reported about the human catalytic antibody light chains possessing catalytic activity, which was mostly encoded in Subgroup II in kappa type. In this study, the highly purified human light chains were submitted to investigate the function of the toxicity against cancer cells. We designed two primer sets and performed a semi‐nested PCR using cDNA prepared from human leukocyte. As the results, eighteen clones of subgroup II germline gene of human kappa light chain were established. The mutants of C220A corresponding to the 18 clones were made. And the wild types and mutants were expressed in E. coli and the light chains recovered were highly purified by two‐step purification system. Out of 18 clones, #1 clone showed the cytotoxicity to both human lung (A548) and human stomach cancer cells (SNU‐1) but not to pancreas cancer cells (PANC‐1). Interestingly, the dimeric form showed the stronger effect than the monomeric form (C220A). The #1 clone could hydrolyze QAR‐MCA synthetic peptide showing the amidase activity. In addition, #1 clone has a unique amino acid sequence compared with that of other clones. Although it is still unclear that the relationship between catalytic activity and cytotoxicity of human light chain (#1 clone) at this moment, the catalytic triad structure of the clone may contribute the anti‐cancer effect.