Modulation of catalytic functionality of alkaline phosphatase induced by semiconductor quantum dots: evidence of substrate-mediated protection

摘要: Enzymes provide the critical means by which almost all biological reactions are catalyzed in a controlled manner. Methods to harness and exploit their properties of strong current interest growing field biotechnology. In view many unique physical optical characteristics that advantageous for studying enzyme activity at quantum dot (QD)–bioconjugate interfaces, we endeavored explore possible influence on conformation catalytic functionality alkaline phosphatase (ALP), clinical marker enzyme, conducting vitro enzymatic assay using molecular spectroscopic techniques such as UV-visible absorption, fluorescence, circular dichroism (CD) Fourier transform infrared (FTIR) spectroscopy. The resulting experimental data were then analyzed context classical Michaelis–Menten model. results show 60% 30% decrease interaction with 10 nM Cys-CdTe or Cys-CdS QDs, respectively, suggesting inhibition dependence particle nature. CD spectra measurements indicated QDs induced α-helical content an increase β-sheet structure ALP, loosening unfolding protein skeleton. Interestingly, when substrate added simultaneously molecules, was significantly reduced indicating protection molecules. Further, demonstrate protein-encapsulated do not affect present study provides valuable information may have significant ramifications various biomedical applications, biosensing, drug delivery, cellular imaging, etc.