New molecular beacon for p53 gene point mutation and significant potential in serving as the polymerization primer

Molecular beacon (MB) is usually explored as a convenient probe for various bioassays. In an enzymatic polymerization-based biosensing system, primer, and MB, sometimes involving other oligonucleotides, are often required to collaboratively generate an amplified fluorescent signal to detect target molecules with high sensitivity and specificity. In the current study, a multifunctional primer-integrated MB (MP-MB) was developed to detect the p53 tumor suppressor gene. Compared with the traditional MB, our MP-MB can not only selectively identify the target of interest and signal sensitively its hybridization event, but also act as the primer during enzymatic polymerization. Specifically, hybridization of MP-MB to target p53 gene restored the fluorescence intensity and activated the pre-locked primer designed by changing the molecular configuration of MP-MB. Moreover, the p53 gene could be detected down to 1 nM with a linear response range of 1×10−9-3×10−7 M, and p53 gene point mutation was readily distinguished from the wild-type one. Its potential application as a primer of replication in enzymatic polymerization-based assay systems was validated by running parallel gel electrophoreses in comparison with the native counterpart of MP-MB without any chemical modification. Owning to its excellent assay characteristics, less species requirement, broad sequence diversity and preserved intrinsic bioactivity, the proof-of-concept of MP-MB exhibits a great potential in various biomedical applications.