Human cyclophilin B (CypB) is oversecreted by pancreatic cancer cells, making it a potential biomarker for early‐stage disease diagnosis. Our group is motivated to develop aptamer‐based assays to measure CypB levels in biofluids. However, human cyclophilins have been postulated to have collateral nuclease activity, which could impede the use of aptamers for CypB detection. To establish if CypB can hydrolyze electrode‐bound nucleic acids, we used ultrasensitive electrochemical sensors to measure CypB's hydrolytic activity. Our sensors use ssDNA and dsDNA in the biologically predominant d‐DNA form, and in the nuclease resistant l‐DNA form. Challenging such sensors with CypB and control proteins, we unequivocally demonstrate that CypB can cleave nucleic acids. To our knowledge, this is the first study to use electrochemical biosensors to reveal the hydrolytic activity of a protein that is not known to be a nuclease. Future development of CypB bioassays will require the use of nuclease‐resistant aptamer sequences.
Human cyclophilin B (CypB) is oversecreted by pancreatic cancer cells, making it a potential biomarker for early-stage disease diagnosis. Our group is motivated to develop aptamer-based assays to measure CypB levels in biofluids. However, human cyclophilins have been postulated to have collateral nuclease activity, which could impede the use of aptamers for CypB detection. To establish if CypB can hydrolyze electrode-bound nucleic acids, we used ultrasensitive electrochemical sensors to measure CypB's hydrolytic activity. Our sensors use ssDNA and dsDNA in the biologically predominant D-DNA form, and in the nuclease resistant L-DNA form. Challenging such sensors with CypB and control proteins, we unequivocally demonstrate that CypB can cleave nucleic acids. To our knowledge, this is the first study to use electrochemical biosensors to reveal the hydrolytic activity of a protein that is not known to be a nuclease. Future development of CypB bioassays will require the use of nuclease-resistant aptamer sequences.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.