@Article{mcb.2020.09595,
AUTHOR = {Hui Yao, Liqun Wang, Jia Guo, Weimin Liu, Jingjing Li, Yingxiao Wang, Linhong Deng, Mingxing Ouyang},
TITLE = {Genetically Encoded FRET Biosensor Detects the Enzymatic Activity of Prostate-Specific Antigen},
JOURNAL = {Molecular \& Cellular Biomechanics},
VOLUME = {17},
YEAR = {2020},
NUMBER = {3},
PAGES = {101--111},
URL = {http://www.techscience.com/mcb/v17n3/39481},
ISSN = {1556-5300},
ABSTRACT = {Prostate cancer is the most common cancer among men beyond 50 years
old, and ranked the second in mortality. The level of Prostate-specific antigen
(PSA) in serum has been a routine biomarker for clinical assessment of the cancer
development, which is detected mostly by antibody-based immunoassays. The
proteolytic activity of PSA also has important functions. Here a genetically
encoded biosensor based on fluorescence resonance energy transfer (FRET) technology was developed to measure PSA activity. In vitro assay showed that the
biosensor containing a substrate peptide ‘RLSSYYSGAG’ had 400% FRET
change in response to 1 µg/ml PSA within 90 min, and could detect PSA activity
at 25 ng/ml. PSA didn’t show enzymatic activity toward the biosensor in serum
solution, likely reflecting the existence of other inhibitory factors besides Zn2+.
By expressing the biosensor on cell plasma membrane, the FRET responses were
significant, but couldn’t distinguish well the cultured prostate cancer cells from
non-prostate cancer cells under microscopy imaging, indicating insufficient speci-
ficity to PSA. The biosensor with the previously known ‘HSSKLQ’ substrate
showed little response to PSA in solution. In summary, we developed a genetically encoded FRET biosensor to detect PSA activity, which may serve as a useful
tool for relevant applications, such as screening PSA activation substrates or inhibitors; the purified biosensor protein can also be an alternative choice for measuring PSA activity besides currently commercialized Mu-HSSKLQ-AMC substrate
from chemical synthesis.},
DOI = {10.32604/mcb.2020.09595}
}