Skip to main content
eScholarship
Open Access Publications from the University of California

Time-resolved fluorescence of apoferritin and its subunits.

  • Author(s): Rosato, N
  • Finazzi-Agro, A
  • Gratton, E
  • Stefanini, S
  • Chiancone, E
  • et al.
Creative Commons 'BY' version 4.0 license
Abstract

The decay of the intrinsic fluorescence of the apoferritin polymer and its subunits has been studied by pulse and phase shift techniques. Both techniques show that the fluorescence decay of all the samples tested cannot be described by a single exponential function. The fluorescence decay data of the apoferritin subunits obtained with either technique can be fitted satisfactorily with a function resulting from the sum of two exponential components. However, the polymer data obtained with the high resolution phase shift technique operated either by synchrotron radiation or by a mode-locked argon ion laser can be fitted better using a bimodal gaussian continuous distribution of lifetime components. The molecular basis for this distribution of lifetime values may lie in the heterogeneity of the tryptophan environment generated by the assembly of the subunits into the polymer. The binding of the first 100 irons to apoferritin quenches the intrinsic fluorescence without affecting the lifetimes in a proportional way. This finding may be taken as an indication that the quenching of the tryptophan fluorescence induced by the binding of iron has both static and dynamic components.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
Current View